Sometimes, when Congress addresses an issue, there's a big fight, and once the matter is resolved, everyone pretty much moves on. This was the case with Bush administration's Medicare prescription drug coverage, and it was the case with President Obama's termination of "don't-ask-don't tell." In those cases, the risks of being wrong on the issue are minimal. Voters have other things to worry about.
Obamacare is not one of those. Two years after it passed, despite President Obama's re-election, Republicans in Congress are still trying to repeal it, and Republican governors are still finding ways to resist implementation. It's a live issue that continues to motivate hard-line GOP voters -- unlike, say, gays in the military.
Immigration reform is likely to be the same. That's partly because the resentment of unauthorized immigrants felt by so many GOP voters will not abate. Those immigrants will still be just as visible as ever, if not more.
It's also because many conservative officeholders will continue to resist letting them become citizens, while constantly faulting border enforcement efforts. Liberals, by the way, may also push to loosen the terms for the path to citizenship. No one is going to move on very soon. No one is going to forget how anyone voted.
If you're a Republican House member from a solidly Republican district, voting for immigration reform is an invitation for constituents to show up at meetings in your district, vehemently complaining. It's also an invitation for an opponent to run against you in 2014 or even 2016, blaming you for a process that will still be unfolding and still be controversial.
There are good policy reasons to vote for reform -- but in the end, the political risks to House Republicans are likely to sink it.