The Senate’s “big, beautiful” vote-a-rama starts in just two hours — and nobody knows how it’s going to end.

Senate Majority Leader John Thune can only lose one more vote with Sens. Rand Paul (R-Ky.) and Thom Tillis (R-N.C.) already opposed. As Senate GOP leaders scramble to strike deals to keep the bill on track, House Republicans are drawing red lines, with fiscal hawks threatening to tank the bill over the Senate’s budget framework and moderates balking at the provider-tax crackdown.

Here are the big fights we’re watching when amendment votes kick off at 9 a.m., leading to a final vote on passage late Monday or early Tuesday:

Medicaid: GOP Sen. Rick Scott’s proposal to curb a key Medicaid funding mechanism after 2030 has Thune’s support as part of a deal struck to get the Florida senator and a handful of other holdouts to advance the megabill to debate.

If it fails, it could cost leadership some fiscal hawks, though Sens. Scott and Ron Johnson (R-Wis.) refused to go there Sunday night. If it passes, it could alienate so-called Medicaid moderates. One of them, Sen. Susan Collins of Maine, filed an amendment that would double the stabilization fund for rural hospitals to $50 billion, and pay for it by adding a 39.6-percent bracket on earners making over $25 million.

Medicaid moderates could also try to further water down the bill’s cut to the provider tax. Keep an eye on Tillis, now unburdened by a reelection bid, who slammed the Medicaid cuts in a fiery floor speech Sunday and might jump in again. Another key player to watch is Sen. Lisa Murkowski and whether her support slips after the parliamentarian derailed Medicaid-payment provisions aimed at winning over the Alaskan. The parliamentarian also, as of early this morning, had yet to rule on food-aid waivers for Alaska that could affect Murkowski’s vote.

Green credits: Moderates including Tillis and Sen. John Curtis (R-Utah) could offer amendments to soften the bill’s deep cuts against wind and solar energy, including its crackdown on IRA credits and a new excise tax. That could provoke a fight with House conservatives and the White House, which have pushed for aggressive rollbacks.

AI: Commerce Chair Sen. Ted Cruz (R-Texas) and Sen. Marsha Blackburn (R-Tenn.) are pitching a plan to cut the megabill’s 10-year moratorium on state enforcement of AI laws in half and make accommodations for internet protections.

The grand finale could be a manager’s amendment that House GOP leaders are pushing for to further resolve differences between the chambers and speed the bill to Trump by Friday. The House is scheduled to vote as soon as Wednesday at 9 a.m.

What else we’re watching:

— Farm bill fight: Dozens of agriculture groups are urging senators to oppose an amendment from Sen. Chuck Grassley (R-Iowa) that would limit income thresholds of farmers who can receive federal aid. A host of farm-state GOP senators also oppose Grassley’s push, according to three people granted anonymity. Some are concerned that liberal senators could join with conservative fiscal hawks to pass the amendment.

— Solar and wind tax backlash: The U.S. Chamber of Commerce and the Solar Energy Industry Association are slamming a new addition to the megabill that would tax solar and wind projects that have components from foreign sources, including China. “Taxing energy production is never good policy, whether oil & gas or, in this case, renewables,” Chamber executive vice president and chief policy officer Neil Bradley wrote on X.

— Campaign announcements: Rep. Don Bacon is expected to announce his retirement Monday, according to two people familiar with his plans. The centrist Republican’s Nebraska seat is a prime pickup opportunity for Democrats; it’s one of only three GOP-held districts Kamala Harris won in 2024. Meanwhile GOP Rep. Dusty Johnson is expected to announce a bid for South Dakota governor on Monday, according to two people familiar with his planning. He’ll be the eighth House Republican to run for higher office in 2026.

Jordain Carney, Meredith Lee Hill, Mohar Chatterjee and Josh Siegel contributed to this report.

Hours after announcing his retirement, Republican Sen. Thom Tillis went to the Senate floor and slammed the GOP’s plans for drastic Medicaid cuts — warning Republicans they are about to “make a mistake on health care and betray a promise” if their sprawling domestic policy bill passes.

“It is inescapable this bill will betray the promise Donald Trump made,” Tillis said. “I’m telling the president that you have been misinformed. You supporting the Senate mark will hurt people who are eligible and qualified for Medicaid.”

Tillis, who opposed the bill on a procedural vote Saturday night and then announced Sunday he would not seek reelection, said he could not vote for the Senate’s bill because of provisions that he said would kick some 663,000 residents of his state off their health care plans. He called on the Senate GOP to jettison its “artificial” July 4 deadline and rewrite the bill.

“I respect President Trump, I support the majority of his agenda, but I don’t bow to anybody when the people of North Carolina are at risk, and this puts them at risk,” Tillis told reporters after he left the floor.

The two-term senator who has been known for working across the aisle said he had done his own research on how changes to so-called state directed payments and a new cap on medical providers taxes would affect his state — contacting state legislative leaders, the state’s Democratic governor, Josh Stein and hospital groups.

Tillis said he also talked to CMS Director Mehmet Oz and presented his findings that showed the best-case scenario was a $26 billion cut in federal support.

“After three different attempts for them to discredit our estimates, the day before yesterday they admitted that we were right,” Tillis said on the floor. “They can’t find a hole in my estimate.”

In his remarks to reporters, he said Trump is “getting a lot of advice from people who have never governed and all they’ve done is written white papers,” adding that he has “people from an ivory tower driving him into a box canyon.”

Tillis, who was elected to the Senate in 2014, compared Trump’s “big, beautiful bill” to the Affordable Care Act: “The effect of this bill is to break a promise. And you know, the last time I saw a promise broken around health care, with respect to my friends on the other side of the aisle is when somebody said, ‘If you like your health care, you can keep it.’”

The Senate is now working through up to 20 hours of debate, before a marathon voting series of amendments scheduled to start Monday morning. Tillis said he might return to the floor to speak against the bill.

Trump lambasted Tillis Saturday night after he voted against opening debate on the megabill, and Tillis said he’d already told Trump at that point he was likely to retire.

“Pretty much what I said on the floor is what I said to the president last night and I stand by it,” Tillis told reporters after the speech, adding later that he told the President he “probably needed to start looking for a replacement.”

“I told him I want to help him,” Tillis added. “I hope that we get a good candidate that I can help and we can have a successful 2026.”

Florida Sen. Rick Scott is circulating text of his amendment to the GOP megabill that would effectively end a key Medicaid financing mechanism after 2030.

The provision won the backing of Senate Majority Leader John Thune during an eleventh-hour negotiating session held Friday night as a procedural vote was held open to win over Scott and other holdouts. It is expected to come up during the “vote-a-rama” set to take place overnight Sunday into Monday where dozens of amendments will be debated and voted on.

Scott said Sunday he’s “very confident that my amendment is going to pass.” Other Republicans are skeptical, with several in the GOP ranks nervous about cutting too deeply into Medicaid.

Under the amendment, the federal government’s 90 percent cost share for Medicaid enrollees made newly eligible under the 2010 Affordable Care Act will end on Dec. 31, 2030. Beneficiaries who were enrolled prior to that date would be grandfathered in at the old rate, but new enrollees would see their medical costs reimbursed at the lower “FMAP” rate, which can be as low as 50 percent, with states picking up the rest.

The amendment is co-sponsored by GOP Sens. Ron Johnson of Wisconsin, Mike Lee of Utah and Cynthia Lummis of Wyoming, as well as Finance Chair Mike Crapo of Idaho.

Senate Republicans are on the cusp of formally adopting a controversial accounting tactic to zero out much of the cost of their massive domestic policy bill.

The matter came to a head on the Senate floor Sunday afternoon, when Democrats sought to prevent the use of the current policy baseline, as the tactic is known. Minority Leader Chuck Schumer objected to the maneuver and accused Republicans of setting a new precedent with the “budgetary gimmick.”

The Senate is set to vote on Schumer’s objection later Sunday or Monday, but Republicans believe their members will back up Senate Majority Leader John Thune and Senate Budget Chair Lindsey Graham (R-S.C.).

That’s in part because they were able to sidestep a situation where senators would be asked to overrule Parliamentarian Elizabeth MacDonough on the baseline question. Instead, Republicans are asserting that Graham has the ability to establish which baseline is used under the 1974 law governing the budget process, rather than having MacDonough issue a formal ruling.

“There is nothing to debate and we consider this matter settled,” Graham spokesperson Taylor Reidy said.

The revised baseline allows Republicans to essentially write off the $3.8 trillion cost of extending tax cuts passed in 2017 that are set to expire at the end of the year. The effect on the megabill’s bottom line is profound as a pair of new Congressional Budget Office reports show.

One, released late Saturday night using the current policy baseline, showed the legislation would reduce the deficit by $508 billion. The other, released Sunday morning using the traditional method accounting for expiring provisions, showed the megabill would increase the deficit by $3.25 trillion.

“Things have never, never worked this way where one party so egregiously ignores precedent, process and the parliamentarian, and does that all in order to wipe away trillions of dollars in costs,” Sen. Patty Murray (D-Wash.) said during a speech on the Senate floor Sunday.

The maneuver came as little surprise. The GOP plan has been quietly in the works for months, and Thune had suggested they would reprise the no-formal-ruling strategy they’d used earlier in the process of passing the megabill.

“As we did on the budget resolution, we believe the law is clear that the budget committee chairman can determine the baseline we use,” Thune told reporters. Graham on Sunday embraced the CBO ruling showing the deficit savings — and his own authority to make the accounting change: “I’ve decided to use current policy when it comes to cutting taxes,” he said. “If you use current policy, they never expire.”

The baseline change is crucial for Senate Republicans because under the budget blueprint they adopted earlier this year, the Finance Committee provisions in the bill can only increase the deficit by a maximum of $1.5 trillion. The bill now under consideration wouldn’t comply under the old accounting method.

Oregon Sen. Ron Wyden, the top Finance Democrat, called it “budget math as fake as Donald Trump’s tan,” and said the GOP amounted to a “nuclear” choice that would weaken the chamber’s 60-vote filibuster.

“We’re now operating in a world where the filibuster applies to Democrats but not to Republicans, and that’s simply unsustainable given the triage that’ll be required whenever the Trump era finally ends,” he said.

Senate clerks have completed a nearly 16-hour reading of the GOP’s 940-page megabill. Clerks began reading the text aloud at 11:08 p.m. Saturday and finished Sunday at 3:03 p.m.

By refusing to waive chamber rules allowing for reading, Senate Democrats hoped to create an opportunity to highlight some of the most unpopular issues in the legislation. Now, under Senate rules, there will be 20 hours of the debate evenly divided between Democrats and Republicans.

Democrats are expected to use their full 10 hours, while Republicans are expected to take only a couple hours. That would mean the vote-a-rama — a marathon series of amendment votes — will begin sometime early Monday morning, though senators could agree by unanimous consent to delay it.

The GOP megabill is by no means finalized. Party leaders continue to negotiate to tweak the bill in ways that will win 51 votes in the Senate while also garnering enough votes to pass in the House later this week without further modifications. Republicans also continue to deal with the chamber’s parliamentarian, who continues to review whether parts of the bill comply with the budget rules the GOP is using to pass the bill along party lines.

White House officials will host Kentucky state Sen. Aaron Reed in the coming weeks for a discussion about challenging GOP Rep. Thomas Massie in next year’s Republican primary, according to two people granted anonymity to describe the private plans.

President Donald Trump and his political operation have been searching for a candidate to challenge Massie over his opposition to the president’s “big, beautiful bill” and his strike on Iran’s nuclear facilities. Trump political advisers Chris LaCivita and pollster Tony Fabrizio have launched a super PAC directed at defeating Massie that’s already running a TV ad attacking the seven-term incumbent.

Massie is embracing the challenge, fundraising off MAGA’s slights and telling reporters last week he raised $120,000 in a single day off of Trump’s threats to campaign “really hard” against him.

Massie — who previously endorsed Reed for state Senate, and whom Reed in return had called “one of America’s greatest Congressmen” — did not immediately return a request for comment. Reed, a former Navy SEAL, was first elected to the Kentucky state house last year.

Sen. Markwayne Mullin is insisting President Donald Trump’s sweeping domestic megabill doesn’t break his promise not to cut Medicaid, even as the Congressional Budget Office estimates 7.8 million people would lose access if it passes.

Instead, Mullin (R-Okla.) told NBC’s Kristen Welker on Sunday, the “Big Beautiful Bill” is eliminating fraud, waste and abuse that Republicans say is rampant in the program.

“What is so hard about having a work requirement there with someone that has no medical conditions and no dependents?” he said on “Meet the Press.” “We don’t pay people in this country to be lazy. We want to give them an opportunity. And when they’re going through a hard time, we want to give them a helping hand. That’s what Medicaid was designed for.”

The Senate GOP voted narrowly to move to a general debate on the package on Saturday. Final passage could come Monday. But one Republican, North Carolina Sen. Thom Tillis, voted against moving the bill forward due to its Medicaid language.

Democrats, too, are looking to seize on the cuts to win back working class voters who have moved toward Trump since his political rise.

Mullin argued that Republicans are seeking to future-proof the program, refocusing Medicaid on what it was “designed for.”

“There’s 35 million people under the poverty line inside the United States,” Mullin told Welker. “And there’s 70 million people that are signed up for Medicaid. You’re going to tell me that there’s not room to cut fraud, waste, and abuse in the program?”

As Republicans in Congress look to get President Donald Trump’s sweeping megabill to the Oval Office by July 4, one Democratic Senator is predicting the bill will crater support for the GOP across the country.

Virginia Sen. Mark Warner told CNN’s Jake Tapper on Sunday that the Medicaid cuts in Trump’s “Big Beautiful Bill” will prove especially unpopular.

“I think the overwhelming amount of data shows that on this one, this is tax cuts for the wealthiest to end up cutting health care, plain and simple,” Warner said on “State of the Union.” “You can put any lipstick you want on this pig, but it’s still a pig.”

Senate Republicans on Saturday narrowly voted to start debate on the megabill, with just two members of the caucus, Kentucky Sen. Rand Paul and North Carolina Sen. Thom Tillis, voting against moving forward. The chamber could likely pass the bill by Monday.

A June estimate from the Congressional Budget Office found that the bill and other health care rules could push 16 million people off health insurance. Warner told Tapper that it would “about double” the uninsured rate in his commonwealth of Virginia.

“The fact of the matter is, what this does baseline is all these cuts, all this cutback on health care to provide the wealthiest in our country a disproportionate share of tax cuts,” he said. “That just doesn’t seem fair. And the more we can get that out, I think this will be a political albatross.”