The surface transportation bill, which passed out of the Senate Environment and Public Works committee on a unanimous vote, has been mired on the Senate floor for close to a month. Senate Republicans have filibustered all efforts to wrap up work on the bill, mainly because they sought a series of bumper-sticker amendment votes to make vulnerable Democrats uncomfortable. They know the bill has broad support and will eventually pass, but if they can hold together on cloture votes, they can block it until they get their way on amendments. Most of them have nothing to do with transportation policy. Fully 1/12 of the Senate’s time this year, then, will be spent on a standoff over squeezing election-year message votes out of the majority. Yeah, the Senate rules are just fine.

A long-sought deal on amendments was finally reached last night. Thirty amendments will be allowed onto the floor for a vote, and then the bill will move to its final passage. This sets up the Senate to jam the House with the bill, something John Boehner may resign himself to passing.

The Senate will begin slogging through the amendments on Thursday, and it’s possible that a vote on passage of the bill could come that night. However, it’s likely that action on the bill will drag over until Tuesday, when senators return from a weekend break.

Reid, a Nevada Democrat, plans to immediately send the bill over to the House, where GOP leaders have been struggling to corral enough votes to pass their own five-year bill. House Speaker John Boehner, R-Ohio, warned rank-and-file Republicans at a closed-door meeting Wednesday that if they don’t act quickly to pass their own bill, he will bring the Senate bill to the House floor for a vote, lawmakers who attended the meeting said.

“You don’t like that? I don’t like it either. Why would any of us like it?” Boehner was quoted as saying by a Republican aide present in the meeting. “It means punting on the opportunity to pass an infrastructure bill that bears our stamp.” The aide asked not to be identified because he wasn’t authorized to speak publicly.

Boehner is about to lose this round if he cannot corral his members.

But what are these amendments that will get votes starting today? A couple are Democratic priorities, like extending renewable energy tax breaks that expired last year. But most of them are Republican message votes. They will vote today on delaying EPA rules on industrial boilers, as well as on a measure that would mandate construction of the Keystone XL pipeline. On the last one, the White House has been lobbying members to block the amendment.

The White House lobbying effort, including phone calls from the president to Democrats, signals that the vote could be close when it heads to the floor Thursday. The president is trying to defeat an amendment that would give election-year fodder to his Republican critics who have accused him of blocking a job-creating energy project at a time of high gas prices.

The amendment, proposed by Sen. John Hoeven (R-N.D.), states that Obama would have no role in such cross-border permitting decisions since, in this case, the pipeline would originate in Canada. The measure would need 60 votes to pass, and Obama has already lost two Democrats who back the proposal – Sens. Joe Manchin of West Virginia and Mary Landrieu – and is at risk of losing more moderates and vulnerable Democrats.

Democrats could lose up to 12 and still carry the vote. The intervention by the White House suggests that they may lose more.