WASHINGTON ― A Republican proposal to add $50 billion in defense infrastructure spending to the bipartisan infrastructure legislation faces headwinds in the Senate — but proponents are already discussing backup plans.

Bipartisan talks on the $1 trillion bill fell apart Thursday night, sending the defense amendment and others into limbo and highlighting the hurdles to passage. The defense amendment would need unanimous consent of all 100 Senators to receive a floor vote and then would likely require 60 votes to be added to the bill.

With billions proposed for shipyard rehabilitation projects, supply depots, nuclear infrastructure and 5G telecommunications gear, the stakes are high. And the sponsors have high profiles: Senate Appropriations Committee Vice Chairman Richard Shelby, R-Ala., is leading the amendment effort along with senior Senate Armed Services Committee Republicans Roger Wicker, R-Miss.; Jim Inhofe, R-Okla.; Mike Rounds, R-S.D., and Thom Tillis, R-N.C.

“We’re negotiating it right now, we’re getting to the waning hours, we’re hoping we’ll get it done,” Tillis told Defense News Thursday evening.

“If not, we’ll probably take another crack at it on another vehicle,” he added, noting that could mean the National Defense Authorization Act.

At the time, the defense amendment was one of 16 amendments in contention during lengthy closed-room negotiations over which would receive a floor vote before the larger bill receives a vote.

“We’re hoping it’s gonna make the cut,” Tillis said, “but we’ve also got to be respectful of other amendments that may be closer to the nexus of the infrastructure bill.”

The next key moment will come Saturday, when the Senate is expected to resume consideration of the bill and the bill’s backers will attempt to overcome a filibuster to end debate. (The Senate won’t consider the NDAA until after it returns from its August recess.)

A recorded vote could help raise the proposal’s profile before broader bipartisan negotiations over government spending this fall. Senate Minority Leader Mitch McConnell, R-Ky., has warned there will have to be equal levels of growth on defense and non-defense spending, though he hasn’t filled in plans for added defense spending.

Republican supporters of the Shelby package see national defense infrastructure as historically neglected and argue defense spending is being shortchanged as Democrats propose massive investments in domestic priorities. According to an aide to one supporter, the military has a $135 billion facilities maintenance deficit.

On Thursday, supporters were frustrated that talks to include the amendment seemed to have stalled.

“I just think it’s absolutely crucial infrastructure and national security assets so it’s entirely justifiable,” Wicker said of the amendment.

“We’re not agreeing to a lot, we’re not agreeing to anything,” said Shelby. “We need to let the people vote on it. Defense infrastructure is important — shipyards, everything.”

With $25.4 billion for shipyards, the amendment would represent a significant windfall for the Defense Department and some of the communities that host its facilities. Of that, $21 billion would be for Navy public shipyards in Norfolk, Va.; Pearl Harbor, Hawaii; Portsmouth, Maine, and Puget Sound, Wash., ― with another $2 billion for private shipyards and $350 million for the Coast Guard yard in Baltimore.

(The proposal overlaps with previous legislation from Wicker, the Shipyard Act, which had backing from several Democrats.)

The amendment would also provide $4.5 billion to modernize supply depots; nearly $4 billion to improve nuclear weapons facilities at Los Alamos, N.M., and Savannah River, S.C.; $4 billion to modernize test and training ranges, and $4 billion to address facilities sustainment, restoration and modernization.

Some $2.5 billion would modernize ammunition plants; another $2.5 billion would fund fifth-generation networking at military bases; $2 billion would fund high-priority military construction projects and $1.5 billion would remediate chemicals used by the military known as PFAS.

The overall proposal dwarfs the $10 billion appropriation House Democrats have proposed for military construction and the $11 billion the Senate Appropriations Committee approved on a bipartisan basis.

At least one Democrat was flabbergasted at Shelby’s proposal.

“The defense budget is already too high, the [Senate] NDAA is already $25 billion larger than President Biden requested and President Biden’s request was to cover operations and infrastructure,” said Senate Armed Services Committee member Elizabeth Warren, D-Mass.

“I am not going to support further increases of the defense budget, whether its through regular channels or back channels,” she added.

That doesn’t mean all Democrats object to it. Maryland Sen. Chris Van Hollen had not seen the $50 billion plan, but said he supports an earlier amendment from Wicker that contained the $25.4 billion for shipyards ― including the Coast Guard project in his state.

“I support the Wicker amendment, I haven’t had a chance to support the other one,” Van Hollen said, adding the Wicker amendment “would help with the Maryland Coast Guard [facility], which is one of the major centers.”

Still, the lead Republican negotiator for the infrastructure bill, Sen. Rob Portman of Ohio, said he anticipates Democrats will deny unanimous consent for a floor vote for the defense amendment. He and other members of the bipartisan gang of supporters for the infrastructure bill have pledged to fend off poison pill amendments.

Whether $50 billion for defense would jeopardize the larger bill is unclear. However, Win Without War Executive Director Stephen Miles speculated in a tweet Thursday that it will cost Democratic support in the House, where the party holds a slim majority.

“Hearing rumblings that Senate Republicans are trying to jam $50 BILLION for the Pentagon at the last second into the Bipartisan Infrastructure Bill,” the tweet read. “There’s no universe where that doesn’t cost a pile of House Dem votes, who already weren’t happy about the bill. Sheer madness.”

Joe Gould is the senior Pentagon reporter for Defense News, covering the intersection of national security policy, politics and the defense industry. He served previously as Congress reporter.

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