Score one for the backers of “one big, beautiful bill.”

House Republicans launched their budget plan out of committee Thursday night — the first legislative step toward fulfilling President Donald Trump’s policy agenda but at odds with the Senate’s continued pursuit of a “two-track” plan.

The House Budget Committee voted to approve a budget resolution along party lines, 21-16, after a marathon markup. In order to rally enough Republican support to push the measure over the finish line, GOP leaders placated fiscal conservatives by tweaking the blueprint that will ultimately allow them to pass a massive bill tackling tax cuts, border security, defense spending and energy policy — all while sidestepping the Senate filibuster.

“This budget resolution provides the fiscal framework for what will be one of the most consequential pieces of legislation in modern history,” House Budget Chair Jodey Arrington (R-Texas) said, “and the principal legislative vehicle for delivering on President Trump’s ‘America first’ agenda.”

The changes to the budget resolution, if adopted by both chambers, would force Republicans to cut more spending in exchange for tax cuts. It could curtail their ability to deliver on Trump’s most prominent campaign-trail promises, like nixing taxes on tips, while also alienating swing-district Republicans uncomfortable with slashing safety net programs like SNAP food assistance to low-income households.

Democrats are already blasting it. “How can my colleagues across the aisle take money that is meant to put food on people’s tables and instead use that money so a CEO can deduct the cost of a private jet?” Rep. Bonnie Watson Coleman (D-N.J.) said during the markup, calling the plan “a betrayal of the middle class.”

A floor vote on the fiscal blueprint is House GOP leaders’ next challenge in the arduous process of unlocking the filibuster-skirting power of reconciliation. The budget measure would allow the House’s tax panel to come up with tax cuts that increase the deficit by up to $4.5 trillion over a decade, while ordering other committees to cut enough from mandatory spending programs to reduce the deficit by $1.5 trillion.

“We do not have a revenue problem in the United States. We have a spending problem,” Rep. Erin Houchin (R-Ind.) said during the markup. “And House Republicans, with this budget resolution that we’ve crafted, are taking steps to try to get us on the right path.”

Because the budget resolution is just 45 pages long and only broadly outlines how much Republicans can grow or shrink the deficit in a final bill, Democrats won’t be able to sharpen their attacks on the party-line proposal until Republicans draft the actual package, which is expected to be hundreds of pages long, if not more than a thousand.

So on Thursday, Democrats on the Budget Committee spent more than seven hours peppering their GOP colleagues with amendments that would nix the committee orders included in the fiscal blueprint. They also branded the GOP plan “the Republican ripoff” and noted that it allows for a $3.3 trillion increase in the deficit over a decade.

“Just think about it. You talk about how bad the deficits are and then say: That’s why I’m voting for the bill that increases the deficit,” said Virginia Rep. Bobby Scott, a member of the budget panel and also the top Democrat on the House Education Committee.

The panel defeated all 32 amendments Democrats offered, including several proposals aimed at stopping Elon Musk and his Department of Government Efficiency from slashing federal funding and accessing federal systems that contain sensitive information about Americans. Democrats also proposed amendments aimed at protecting funding for in-kind food assistance programs, Meals on Wheels and other initiatives funded through block grants to states for social services.

Of the two Republican amendments offered Thursday, both were adopted. One, the compromisethat won the House Freedom Caucus endorsement of the resolution, would shrink the amount of tax cuts Republicans can enact if they don’t cut $2 trillion in spending at the same time. The other would ensure Republicans include the text of the REINS Act in their final reconciliation bill. That measure, a perennial favorite of congressional Republicans, would curtail federal rule-making across government.

If House Republicans can adopt the budget resolution on the floor later this month, they stand to increase their clout in the ongoing debate with Senate GOP leaders over how to package their party-line ambitions.

Almost four weeks into Trump’s presidency, House Republicans are still demanding one whopping package that includes trillions of dollars worth of tax cuts, while Senate Republicans root for a plan that leaves tax cuts for later and first delivers border security, defense spending and energy policy. Even Trump’s top advisers and Cabinet officials remain divided.

In the Senate, Budget Chair Lindsey Graham of South Carolina sent a message to his House counterparts during his own budget markup this week: “I hope you will consider what we do if you cannot produce the one big, beautiful bill quickly.”

Graham’s budget, which would pave the way for one slimmer bill now and then another later, could come to the Senate floor as soon as next week. The House is due to schedule a vote on its proposal the last week of February.

If Republican leaders want to enact any major legislation without input from Democrats in the GOP’s first months with “trifecta” control in Washington, Republicans will need to quickly unite around one strategy. Neither chamber can advance a final package until both approve an identical budget measure to unlock the reconciliation power they need to skirt the Senate filibuster. Of course, both chambers also have to pass the same final bill to clear it for Trump’s signature.