The Republican Party desperately needs to change its image among Latinos, who remain a bulwark of strength for the Democrats as as their numbers collapse among whites. But conservatives keep trying to force their candidates to talk tough on illegal immigration:

Mitt Romney opened his town hall meeting here talking about the economy — his thoughts on growing business, getting government out of the way — just as he does nearly every other campaign event. But when he opened last week’s forum for questions, the first voter he called on didn’t seem concerned about any of that. He wanted to know the Republican presidential candidate’s stance on border security.
A similar scene played out in South Carolina a few days later, when Rep. Michele Bachmann (R-Minn.) attended a town hall meeting she assumed would center on the economy, jobs and the federal deficit — only to see the assembled voters react most passionately to her comments on illegal immigration. ...
“Immigration is not even close to the top issue for most Republicans today, but it is an issue that is heavy with symbolic importance to Republican voters,” said GOP pollster Jon Lerner, who advised Tim Pawlenty until he dropped out of the race last month. “If a candidate is squishy on immigration, that symbolically suggests that he’s probably unreliable on a whole host of other conservative issues.”

It will be interesting to see whether, and to what degree, the eventual nominee can get through the primary without having committed himself substantively or rhetorically to positions that will alienate the Hispanic vote. Mitt Romney's best opening against Rick Perry is to attack the Texas governor for his reasonable position on illegal immigration. Does Romney take that line? And if Michelle Bachmann is to avoid what looks like a slow slide into eclipse by Perry, immigration may be her best issue, too.

Update: Somehow I missed Ed Kilgore making this point better and firster.