Conservatives have drawn a bull's eye on the immigration bill passed by the US Senate, insisting the landmark measure will fail as is and vowing political retribution against Republicans who voted for it.
The bipartisan immigration reform bill passed 68-32 in the Senate Thursday with support from 14 Republicans, many of whom now face accusations they let down conservatives opposed to legislation that lays a pathway to citizenship for 11 million undocumented people.
Those lawmakers, including high-profile figures like Senator Marco Rubio, "will have to go back home and explain the votes they cast, and explain to their constituents why it's not amnesty, even though it is," Dan Holler of Heritage Action, a lobbying arm of the conservative Heritage Foundation, told AFP on Friday.
"In a very real sense, the Senate passage of the Gang of 8's bill killed what we think is any hope for real immigration reform."
The four Republicans who joined four Democrats in crafting the legislation were well aware of the potential political pitfalls, perhaps none more than Rubio, a potential 2016 presidential candidate who has been a darling of the small-government tea party movement.
"It's been a real trial for me," Rubio said candidly on the Senate floor this week, acknowledging that his office has been flooded with phone calls and emails by "increasingly unhappy" voters.
Conservatives worry about the bill's $46 billion price tag, and they are skeptical about a Congressional Budget Office report which estimated that the bill would lead to dramatic deficit reduction.
Equally important, many see the Senate making the same mistakes that plagued 1986 legislation, when Congress approved an amnesty for three million undocumented workers on the condition that border security and enforcement was tightened.
Those conditions were never met, and millions more slipped illegally across the US-Mexico border or overstayed their visas. Conservative lawmakers now warn that immigration reform is doomed if it once again puts legalization before border security.
"The Senate #immigration bill is a mistake. Border security, not amnesty, is the answer," congressman Phil Gingrey said on Twitter.
Obama, on a trip in Africa, called House Speaker John Boehner in a bid to nudge him to take up immigration reform.
Boehner has already said the chamber will not take up the Senate bill but seek to pass its own legislation with tougher border security measures.
House Judiciary Committee chairman Bob Goodlatte insists on a piecemeal approach, and his committee has approved four bills, including one that gives state and local government broad interior enforcement powers.
But the most controversial element of potential reform, what to do with 11 million people living in the shadows, has yet to be addressed.
"Chairman Goodlatte does not believe in a special pathway to citizenship," a Judiciary aide said.
Lawmakers headed back to their districts for a week-long break, and some Republicans like Tennessee's Senator Bob Corker will find the welcome mat missing.
Corker co-authored the pivotal amendment that dramatically boosts border security, and while his important role helped bring some skeptical Republicans on board, it angered hard-line conservatives.
"I think most tea party members feel completely betrayed" by Corker, Nashville Tea Party president Ben Cunningham told the Jackson Sun.
Some tea party activists have openly called for conservatives to challenge Republican Senators in upcoming primary elections if they voted for the "amnesty" bill.
"There's probably concern about primaries" in the House too, noted a Republican congressional aide.
The party's 2012 presidential candidate Mitt Romney was ridiculed when he said "self-deportation" was a viable policy for illegal immigrants.
But even after Obama won re-election and Republican leaders called for outreach to minority groups like Hispanics, die-hard conservatives have largely resisted the Senate's immigration reform.
And yet immigration reform obstructionists could face their own backlash.
"We were at the edge of the Jordan River, but after the Senate, we officially got our feet wet," Reverend Samuel Rodriguez, president of the National Hispanic Christian Leadership Conference, told the New York Times.
"If 11 million immigrants are left in the middle of the water and do not reach the promised land, neither will the Republican Party reach the promised land of the White House."