Texas Sen. Ted Cruz and Democratic Rep. Beto O’Rourke both played a big role crafting Congress’s sweeping military improvement plan this month — a package that inspires rare political unity of Capitol Hill.

Now each man faces an awkward political decision over the battle to pay for their much-hyped advancements — an issue that still bitterly divides the two parties in Washington.

Texas is home to roughly 160,000 military service members, and Cruz and O’Rourke spent months working on a defense policy plan tailored to the service personnel needs. The final product includes an order for 77 F-35 aircraft, which are assembled in Fort Worth, plus the largest pay increase for service members in recent history.

But Cruz and O’Rourke are also in the middle of a closely-watched U.S. Senate race that’s pushing them into their partisan corners as Congress considers how to fund the defense plan.

Each man serves on their respective chambers’ committees in charge of writing the law to set the nation’s defense policies. The package they helped create in those roles easily passed the House Thursday, and is expected to be approved by the Senate in the coming weeks.

“There are very few partisan issues in the defense bill,” O’Rourke said in an interview with the Star-Telegram Tuesday. “It’s not completely free of them, but it’s remarkably one of the last places where Congress works.”

The defense bill they worked on lays out the blueprint for defense projects, but separate legislation is needed to actually fund those programs, setting up an age-old political battle on Capitol Hill this fall.

Republicans want to significantly boost defense spending, while simultaneously cutting domestic programs. Democrats say they also want a strong defense budget, but it has to be paired with robust domestic spending.

Neither side is likely to get its way completely from a Senate that needs both Republicans and Democrats to pass big spending bills for the coming fiscal year, which begins Oct. 1.

Republicans control 51 seats in the Senate, but major legislation needs the 60 votes needed to limit debate.

Senate leaders are currently mulling a deal that would pair money for this week’s defense bill with funds for health, education and labor programs, one of many spending measures they plan to take up this fall.

Cruz, who has long championed strict limits on federal spending, already rejected a similar deal earlier this year when leaders agreed to set spending levels. That $1.3 trillion agreement included a $128 billion increase for domestic spending, along with a $160 billion increase for defense over the next two years.

“I voted against that bill, I think it was a mistake,” Cruz told supporters at a rally in Waco earlier this month.

“[I]t included the single biggest rebuilding of our military since Ronald Reagan… That was important, it is a dangerous world,” said Cruz.

“The price that [Senate Minority Leader] Chuck Schumer and the Democrats demanded of that was a massive increase in non-defense spending,” he added.

O’Rourke, whose ambitious Senate bid has caught the attention of a national liberal base, faces pressure to do exactly that this fall.

The left wants Democrats to use defense as leverage for domestic spending, something O’Rourke suggested in an interview this week he isn’t likely to give them.

“I share the concerns about how badly we need investment in domestic programs and infrastructure,” O’Rourke said of that dynamic earlier this week. “But at the end of the day, especially given the fact that we have so many service members from Texas deployed all over the world… I’ve got to do my best to get to the best possible result.”

At stake in the bill’s passage are dozens of provisions both men spent months pushing for on behalf of their state.

Cruz crafted a part of the bill that offers support for the F-16’s flown by the 301st Fighter Wing at Joint Base Fort Worth. Another provision he worked on with Sen. Elizabeth Warren, D-Massachusetts, would make National Guard officers eligible for back pay on their rank promotions.

O’Rourke is particularly proud of a piece he wrote with Rep. Jodey Arrington, R-Texas, that provides counseling and other services to military members transitioning to civilian life.

O’Rourke also pushed for a provision ensuring military criminal records are entered into the national firearms screening database — something he says would have prevented November’s Sutherland Springs, Texas, shooter from being able to pass a gun background check. Twenty-six people died when a gunman opened fire at a church.

Both Cruz and O’Rourke were both chosen by their party’s leaders to serve on the panel that negotiated differences between the House and Senate plans behind closed doors earlier this month.

At the meeting of lawmakers, O’Rourke said he “shared those issues that were most important” and that he “wanted to see in the final conference report.”

Cruz, who is demanding debates for this fall’s election be held on Friday nights when the Senate is out of session, did not attend the meeting.