After considering several iterations of legislation aimed at rebuilding the nation’s crumbling infrastructure paid for by increased energy production, leadership privately concedes they’re at a standstill and don’t know what to do.

They originally planned to have the bill completed by mid-February. Now, it won’t even be on the floor next week. Many Republicans involved say a stopgap measure to avert a shutdown of the nation’s infrastructure building apparatus on March 31 is likely. But there are only 12 legislative days left before current policy expires.

The problem lays bare a simple reality: Boehner and other GOP leaders failed to gauge what their conference would be willing to support. They are, in fact, rewriting the way the nation funds transportation, which is backed by powerful lobbies.

For past bills, party leaders were able to buy off support by throwing money at local projects. Now, in an era of austerity, lawmakers can’t claim a new bridge or highway — they have only the policy change to point to.

“I don’t think the bill was as vetted as it could’ve been,” said Rep. Aaron Schock (R-Ill.). “So I think that process is taking place now.”

The Republican leadership spent much of the past two weeks trying to get members to support a five-year highway bill authored by Transportation and Infrastructure Chairman John Mica (R-Fla.) and prescribed by Boehner. They’ve toyed with the length of extension and the price to garner more support on the floor.

But nearly 100 Republicans have voiced opposition to the Mica bill after several weeks of whipping by leadership.

Concerns run the gamut. GOP leadership likes to say this bill doesn’t have earmarks, but the concerns are still overwhelmingly parochial.

For example, pockets of lawmakers disagree with the ban on double-decker horse carriages — it hurts the West and rodeos, they say. Others have concerns over how the bill handles roads on Native American reservations, and a large group of members take umbrage with the way Republicans proposed eliminating dedicated funding from the Highway Trust Fund for mass transit.

“All these little segments that have a problem they don’t like, they’re holding up the whole bill because of that,” said transportation committee member Rep. James Lankford (R-Okla.).

Another internal problem, according to some, is Mica himself. He announced a primary challenge to freshman Florida Rep. Sandy Adams in the course of trying to get his bill passed.

“It not only sets a horrible example but opens the door to any other member when a chairman of a major committee decides to run against whoever they want within the conference,” a House Republican freshman said, speaking anonymously because he fears Mica’s retribution.

Faced with a lack of support for the longer bill, Republican leadership floated an 18-month extension that fared little better. Boehner now simply calls it a “fallback.”

After gripes by some about his hands-off approach, Boehner has taken an increased role in the process and spent some time with freshmen this week talking about the transportation bill. He spoke about the troubles with getting the bill passed when there are no earmarks for projects, according to several sources present.

During a question-and-answer session with Boehner — dominated by talk of the transportation bill — the speaker repeatedly deferred questions to Majority Whip Kevin McCarthy (R-Calif.), several sources in the room recalled.

“Kevin’s here; he’ll take over,” Boehner said. Another source said Boehner simply asked McCarthy to explain the pockets of dissent within the conference.

None of this is new. House Republicans have had trouble passing bills all year — everything from government funding measures to averting a downgrade in the country’s debt rating.

But this bill is a must-pass for Republicans — politically and substantively.

Highway programs expire at the end of March, and if the House cannot come to terms with how it wants to extend the funding, states will no longer get reimbursed for their highway projects. And without new pay-fors, the HTF could become insolvent by the end of the year, forcing a dreaded transfer from the general fund.

Politically, senior House Republican aides cringe when they think about the optics of letting highway funding expire — especially after enduring a two-week partial shutdown of the Federal Aviation Administration last summer. Not passing a highway bill would be a disaster, they say. Republicans had been selling the transportation bill as this year’s main “jobs bill” but have since christened a package of business legislation as the JOBS Act.

Right now, House Republican aides say four options are in play.

First, they could pass a clean extension of the highway funding. That would be akin to waving the white flag for many.

Second, they could put Mica’s bill on the floor with the expectation that it would fail.

Third, they could aim for some sort of middle ground — perhaps an 18-month extension that ditches the mass-transit reforms, borrows pay-fors from the five-year bill and allows the rest of the money to go toward deficit reduction. That would also likely fail.

Fourth, they could pass the Senate’s two-year transportation bill — assuming the Senate can pass it first. That would be another disappointment; Mica has in the past referred to a bill of this length as merely an “extension,” and Republicans are still pushing for more years.

“Certainly, transportation bills in the past have been for six years, and ones that are less and have a dubious way of paying for it in 10 years presents problems,” Rep. Tom Rooney (R-Fla.) said, describing the perils of the offsets and revenue raisers in the Senate bill.

Democrats are watching this, giddy at the GOP’s failure. Rep. Earl Blumenauer (D-Ore.) said the bill’s breakdown allows his party to get heard, especially “if it encourages the Republicans to think responsibly.”

Rep. Russ Carnahan (D-Mo.), a transportation committee member, said the time crunch might force Republicans to speed up.

“This place, like it or not, works better on deadlines,” Carnahan told POLITICO. “We need to take advantage of that deadline.”

Schock, from industry-heavy Peoria, Ill., called a divisive fight over transit funding a “holy war that’s just unnecessary.”

“It’s like the primary process,” Schock said. “You want the finished process; you don’t like the sausage making.”

Adam Snider contributed to this report.