Some Republican lawmakers are increasingly facing a tough choice – support a comprehensive immigration bill and face a backlash from their own voters or oppose efforts to provide a path to citizenship for undocumented workers and contribute to larger GOP losses in the future.    

Republican strategists are already fretting about the long-term implications for the party if they reject a comprehensive immigration bill, but that’s a bitter pill for conservative activists to swallow, who are promising primary challenges and substantial blowback if lawmakers back reform. 

With fewer and fewer competitive House districts and Senate lawmakers who voted for the reform bill passed last week already facing threats of primary challenges, conservative activists are threatening to kill the effort, and it’s one reason GOP leadership and House Speaker John Boehner has been hesitant to even bring up the Senate bill for a vote. 

Practically speaking, immigration’s failure or success will likely have little bearing on the partisan outcome of the 2014 midterms. Lawmakers’ individual primary re-election concerns, mostly in the House, is what’s driving much of the resistance to a bipartisan immigration bill that would provide a path to citizenship for 11 million illegal immigrants. 

But Republican leaders, who began pushing for reform after they lost the White House in 2012, know the bill’s demise could be a greater omen for 2016, when the GOP faces a growing Hispanic electorate that’s sure to be even more important in the next presidential election.

One national GOP strategist called the current debate “a mild short-term headache for which the party can take two Advil,” and noted it wasn’t as contentious as 2006, when another attempt at reform fell flat. Back then, a bill passed the Senate – when 23 GOP senators voted for it, compared to 14 last week —  but the bill died in an even less-conservative House controlled by Democrats. 

Without a majority of the caucus behind the bill the Senate passed last week with a 68-32 vote, Boehner has said he won’t bring the bill to the floor. Many Republicans still remain optimistic the bill still has a path forward, whether in conference committee or through a new bill from a bipartisan working group in the House. 

But with the conservative base now abuzz in opposition to an immigration bill they say is akin to amnesty — despite the 10 years it would take to get a green card, and another three-year waiting period before immigrants can apply for citizenship – lawmakers in safe districts could especially feel the pull in 2014 — and that’s fueling much of their skepticism.

“These people aren’t controlled. They’re doing their own thing,” said another national Republican consultant of House members already up in arms against the bill. “Primary challenges come from conservative districts, and they don’t care if they upset leadership because there’s no consequences.” 

Party leaders know immigration is a problem they must come up with a solution too before demographics move even further away from them in the coming decade. In their post-2012 autopsy, the Republican National Committee wrote that the GOP “must embrace and champion comprehensive immigration reform” to reach out to the Hispanic community, and  “if we do not, our Party’s appeal will continue to shrink to its core constituencies only.” 

Potential 2016 hopefuls have had to do a delicate dance, too. Former House firebrand Allen West has threatened a primary challenge against Florida Sen. Marco Rubio. Another possible candidate, Kentucky Sen. Rand Paul, voted against the measure, saying it wasn’t tough enough on border security though he’s indicated in the past he could support a pathway to citizenship.

Jonathan Ernst / Jonathan Ernst / Reuters

A group of immigrants and activists for immigration reform, led by Service Employees International Union (SEIU) and CASA, gather to march to urge congress to act on immigration reform, on Capitol Hill June 26, 2013.

Further alienating Hispanic voters could have a bigger impact in a presidential year for the GOP though. In 2012, Latinos made up 10% of the electorate — and voted 71% for Obama, according to national exit polls. That’s an uptick from 2008, when 9% of the national electorate was Hispanic, and voted 67% for Obama.

In 2010, a GOP midterm wave year though, the numbers were better for Republicans. Latino voters made up just 8% of the electorate, and 60% of those said they supported Democrats. But with the economy and health care dominating the conversation, just 8% of all voters said illegal immigration was the most important issue.

Democrats see it as another issue where they can point to a dysfunctional Republican Congress, hoping that positioning themselves as the party of compromise can help their brand even as they face fewer competitive House seats.

Last week, the Democratic Congressional Campaign Committee sent a memo to its caucus pointing out 23 “persuadable” GOP lawmakers who represent significant Hispanic populations and would be “out-of-step with major groups in their districts if House Republicans fail to deliver a solution.”

Many of those are in competitive or potentially competitive House seats, including California Republicans Gary Miller, David Valadao and Jeff Denham. Miller, arguably the most vulnerable GOP incumbent, sits in the most Democratic seat held by Republican, and only won re-election with help from an election fluke after no Democrat advanced past the state’s new top-two primary. Other vulnerable incumbents, including Colorado Rep. Mike Coffman, New York Rep. Michael Grimm and Nevada Rep. Joe Heck, are also targeted

A coalition of immigrant and labor groups are also targeting House leadership with radio ads and on social media, hoping to push the House to a vote.

But Democrats aren’t just looking for a solution — they’re looking for ammunition too. This week the DCCC also launched RepublicansInTheirOwnWords.com — inviting submissions for outlandish GOP statements “so members of the public can peruse House Republicans’ positions on immigration – in their own words.”

These races likely won’t be won or lost on immigration alone, with the economy, health care, and a variety of other important issues coming into play — and there’s no guarantee even Latino voters will base their vote solely on an immigration vote, but to Democrats it plays into a greater message of a worsening GOP brand.

This story was originally published on Fri Jul 5, 2013 12:38 PM EDT