Senate Minority Leader Mitch McConnell said publicly this week that he’s undecided on the bill, but many of his allies view the proposal’s new requirements for rail staffing and inspection as anathema to the party’s long-held small-government stance. As Sen. John Cornyn (R-Texas) put it: “It seems like it’s just too much government regulation.”

“There are some things that were added simply to kind of get the unions on board with it,” Senate Minority Whip John Thune (R-S.D.), a former Commerce Committee chair, said of the bill. Thune added that some of its provisions “are very objectionable from the regulatory standpoint, and handing a whole ton of power over” to the Biden administration.

The derailment of a Norfolk Southern train in East Palestine, leading to a release of toxic vinyl chloride that was later burned, is now more than five months in the rearview mirror. While the response bill is on Majority Leader Chuck Schumer’s agenda, there’s no immediate plan to take it up on the Senate floor given the unclear GOP whip count.

And after a two-year period of reaching unexpected compromises with Democrats, McConnell’s 49-member GOP conference may not be in that mood anymore. Surprising upstart players like Vance and Sen. Josh Hawley (R-Mo.) are left to try to cut a deal with incumbent Democrats like Brown and Bob Casey of Pennsylvania.

“I’m not surprised that certain members of leadership don’t like the bill. But I feel very confident we have the votes,” Vance said. “It’s, frankly, where the party is going. We’re going to do things like this that are good for our voters.”

Republican leaders want Vance to push Democrats harder to drop some of the bill’s regulation and crew mandates. Vance counters that he already has colleagues who haven’t revealed they’ll vote yes when the bill comes to the Senate floor, surmising it could get as many as 65 votes under the right conditions.

But other fellow Republicans suspect Vance’s bill might be getting quietly shelved by his own party. After all, it’s been two months since any new Republicans have come out in support.

“J.D.’s gotten the classic runaround here, which is: ‘We want to work with you. We want to work with you,’ then they try to kill it in committee. And now they’re slow walking on the floor,” said one Republican senator who was granted anonymity to discuss the legislation. “What I’m told is that there are not 60 votes.”

Several other bills that Schumer’s eyeing could prompt similar Republican discord if they’re brought to the floor soon, including a cannabis banking effort, drug pricing legislation and an attempt to regulate artificial intelligence.

But the rail bill is top of mind for Vance and other supporters because it already saw bipartisan passage in committee, the last stop before it can be brought to the Senate floor. However, only two Commerce panel Republicans voted yes: Vance and Sen. Eric Schmitt (R-Mo.). All told, seven Republicans publicly support it.

Frequent bipartisan collaborators like Sens. Susan Collins (R-Maine) and Lindsey Graham (R-S.C.) are noncommittal on the bill, and no members of leadership support it. Sen. Marco Rubio (R-Fla.) is the only GOP supporter of the bill who has served multiple Senate terms.

Graham said he wants to discuss the bill with Sen. Ted Cruz (R-Texas), the Commerce Committee’s top Republican. He’s unlikely to get a positive recommendation: Cruz said the bill needs amending to protect the ability of shipping energy products by rail and warned that a narrow Senate passage doesn’t bode well in the House, where GOP leaders are also highly skeptical of passing new regulations.

“At some level, it doesn’t really matter whether they’re at 60 or 59. Because the bill as drafted will never become law,” Cruz said in an interview. “The sponsors of the bill have to decide: Do they want a press release? Or do they actually want to pass legislation? And at least so far, they’ve been unwilling to make a deal.”

Brown cited the railroad lobby’s influence with GOP leaders as a key reason that the bill is still short of 60 votes. He acknowledged, however, that it would be risky to try to force the rail measure through without more Republican backers.

And he’s deeply skeptical of how McConnell views the legislation.

“We’re not going to go to the floor and lose,” Brown said. “McConnell is a master at making it look like 60 [votes]. And all of a sudden it’s 58.”

McConnell has been careful not to tip his hand on the legislation. Asked this week about his position on the bill, he replied that “I haven’t made a decision personally, and I’m not sure the majority leader’s made the decision to call it up.”

The calculus for McConnell looks clearer, though, in light of his conference’s opposition: If he were to endorse the bill, it would almost certainly surpass the 60-vote threshold. At the same time, many Republicans suspect that McConnell would have a hard time supporting it as written. So with no clear plans to put the bill on the floor, the GOP leader may see little upside to staking out a position while much of his conference either opposes it or remains undecided.

In addition, McConnell often defers to his committee ranking members and closest allies. So when Thune and Cruz are on the same page against the current version, it’s likely to give many Senate Republicans pause. Most are careful to note that if the bill changes, the GOP could give it a big bipartisan approval vote.

“There’s a lot in there I like,” said Sen. Shelley Moore Capito (R-W.Va.), a member of the leadership team. “I think it can be pulled together to get my support.”

But without changes, a floor vote would be a big gamble at best. As another Republican senator put it: “If we saw support growing, then I would expect that we would whip against.”