The chances of comprehensive reform to the nation's immigration system — once thought to have broad, bipartisan support — are quickly disintegrating.
Legislation in both the House and Senate have run into major roadblocks. Sen. Marco Rubio (R-Fla.), who helped write the original legislation, says that the bill in the Senate needs to be improved before he can vote for its passage. Meanwhile, Rep. Raul Labrador (R-Idaho), a member of the House's "gang of eight," dropped out of talks with the group late Wednesday.
Rubio and Labrador are the respective keys to immigration reform passing each chamber of Congress. Both are the conservative members of the respective "gangs of eight," and both are instrumental in getting a large majority of Republicans to vote for the measure.
What is threatening to torpedo the immigration bill in the Senate is an amendment that Sen. John Cornyn (R-Texas) is preparing to introduce next week, which would replace an entire section devoted to border security and beef up the "triggers" on security to enact a pathway to citizenship.
Rubio supports the amendment and has been working on it with Cornyn, but Senate Democratic aides have begun to signal that it's the sort of "poison pill" amendment that could derail legislation in the chamber.
Cornyn's amendment attempts to take Rubio further to the right on the immigration bill, and it threatens to bring other Republican senators along.
One senior Democratic Senate aide, however, questioned how many Republican senators would flee the bill if Rubio jumped ship. Many Republicans, the aide said, consider their political lives to "depend on this bill passing."
"I think there are some Republicans who know that their political survival depends on this bill passing, and are concerned at what appears to be some backsliding within their party," the aide said. "They may want to send a signal that this bill is going to pass, period."
The aide added: "It will be fascinating to see if Republican senators undercut [Rubio's] position that the bill has to be improved to pass by starting to come out for the bill as-is. If that happens Rubio will look a little silly."
In the House, meanwhile, Labrador has backed out of the "gang of eight" because of a conflict on undocumented immigrants' access to health care.
"After today’s meeting, the framework of the bill has changed in a way that I can no longer support," he said in a statement Wednesday night. "Like most Americans, I believe that health care is first and foremost a personal responsibility."
The dynamic in the House, however, hasn't changed much. Although Labrador would have been instrumental in bringing some House conservatives along in favor of the bill, it's likely that immigration reform's chances of success hinge on whether House Speaker John Boehner will bring the bill to the floor without a clear majority of Republican votes.
A Senate aide said that the first floor debate on the immigration bill will come on Friday.
Please follow Politics on Twitter and Facebook.
Join the conversation about this story »