On Friday, House Republicans narrowly passed their version of an annual defense bill 219–210, after stacking it with controversial amendments on social issues that are dead on arrival in the Senate.

The debate on the National Defense Authorization Act, or the NDAA for short, now heads to the Democrat-controlled upper chamber, which is set to consider its own take on the bill later this month. Eventually, the two chambers will work to reconcile their differences between the two in the hope of finding a compromise.

The NDAA, one of Congress’s must-pass bills, effectively lays out what the military’s budget could look like for the next year and which programs will be funded. This year’s House bill authorizes $886 billion in funding, including a 5.2 percent pay raise for service members and the appointment of an inspector general to oversee Ukraine funding.

Much like the debt ceiling legislation and annual spending bills, the NDAA is a prime opportunity for lawmakers to add unrelated amendments making policy changes to pet issues, since it has to pass every year. This week, Republicans capitalized on this opportunity to put forth controversial amendments favored by their right flank, including restrictions on abortion and LGBTQ rights. It’s a move that’s meant to send a message about their position on social issues, and it’s also one that makes what was a bipartisan bill much more contentious.

As House Minority Whip Katherine Clarke put it in a CNN appearance, “This bill has been transformed into an extremist manifesto.” The changes ultimately prompted Democrats on the Armed Services Committee to take the notable step of opposing it after many had backed a prior version. In addition to spurring opposition from Democrats, several amendments that Republicans considered also put GOP divides on full display when it came to issues like Ukraine funding and abortion.

While Congress is probably on track to eventually approve a version of this bill, Republicans’ insistence on including “culture war” amendments will likely make the process more contentious.

“I think ultimately Pentagon funding isn’t at risk, but what we know is happening at least here in the House of Representatives is that there is a relatively unserious effort at trying to make substantial changes to what is usually a must-pass wholly bipartisan piece of legislation,” Rep. Abigail Spanberger (D-VA) told Bloomberg.

What is the NDAA for, and why are the GOP amendments so controversial?

The NDAA lays out how funds for the military can be used and provides important guidance about the policies the Defense Department will focus on. Actual spending for the military is approved via the appropriations process, which has its next deadline this fall, but the authorization bill provides a roadmap for the Defense Department’s budget.

The NDAA addresses everything from service members’ benefits to funding for military equipment to investments in new technology and more.

In recent cycles, both parties have used the legislation to address unrelated issues, in part to score political points. This time was no different. Thursday, Republicans — under pressure from hard-right members — pushed votes on several amendments aimed at advancing a message on different culture war issues.

Chief among these was an amendment that rolls back the Defense Department’s commitment to paying for abortions for service members who travel to obtain them, which passed 221–213, with Republicans and one Democrat (the anti-abortion Texas Rep. Henry Cuellar) voting in favor. Another amendment — which passed 222–211 — would deny funding for gender-affirming surgeries and hormone therapy for trans service members. And a third amendment that passed 214–213 was dedicated to getting rid of the Pentagon’s office on diversity, equity, and inclusion.

Freedom Caucus and other far-right members welcomed these additions and signaled on Friday that they increased their support for the bill. “It has improved dramatically,” Rep. Scott Perry (R-PA) told reporters.

In addition to its focus on social issues, Republicans also weighed several amendments on reducing support for Ukraine, a position a growing proportion of the caucus supports. These amendments wound up failing, with one voted down 341–89 and another rejected 358–70. That those amendments received any backing at all, however, underscored how many Republicans have become resistant toward aid to Ukraine.

How has this split Republicans?

Although the amendment to curb military funding for abortion was broadly backed by Republicans, at least one moderate member complained about the linking of the defense bill with this issue. Rep. Nancy Mace (R-SC) reportedly argued that the two shouldn’t be tied together and that it made the NDAA more partisan.

“We should not be taking this fucking vote, man. Fuck,” Mace reportedly told a staffer, according to Politico. “It’s an asshole move, an asshole amendment.” Mace went on to tell the publication that she was concerned Republicans weren’t doing enough regarding policies that could help women on issues including rape kits and child care costs. She ultimately backed the bill, however, arguing that doing so was necessary to show support for the military.

“It’s not going to pass the Senate anyway; it doesn’t matter,” Mace said. “So if you vote against the NDAA, you’re going to be voting against the men and women in uniform.”

The Ukraine amendment votes also renewed attention on how split the party has been on the extent the US should involve itself in the Ukraine-Russia war. Seventy GOP lawmakers voted to cut off aid to Ukraine entirely and a substantial number rejected cluster munitions for the country. Although many traditional Republicans have backed the Biden administration’s commitment to Ukraine aid, a contingent of conservatives have questioned the need for this support — which has topped $75 billion — and argued that such funds should be used domestically instead.

“My amendment is going to lose overwhelmingly when it is put up for a vote,” Rep. Matt Gaetz (R-FL), who sponsored the provision cutting off aid to Ukraine, said in a floor speech. “But the American people will see who wants to represent them, and who wants to represent Crimea.”

What could this mean for the fate of the bill?

Prior to the addition of these amendments, the NDAA passed on a bipartisan basis out of the House Armed Services Committee. After they were included, though, it received mostly partisan support in the House-wide vote.

“What was once an example of compromise and functioning government has become an ode to bigotry and ignorance,” Armed Services Democrats said in a statement.

The partisan nature of the House bill indicates that negotiations with the Senate will probably be contentious as lawmakers try to find a version that’s workable for both parties. Senate Democrats are likely to completely reject the House’s culture war proposals, but may need to find points of compromise with Senate Republicans due to Democrats’ slim majority in the upper chamber.

Congress has been able to pass the NDAA since 1961, so lawmakers will likely identify a path, though the process to do so could prove thornier than in years past.