In 2008, Republican Sen. John McCain of Arizona lost the Iowa caucuses badly in large part because of his support for the failed 2007 comprehensive immigration plan. During the most recent presidential election cycle, Texas Gov. Rick Perry drew fire from the right over his support for in-state college tuition for children of illegal immigrants. By contrast, Mitt Romney took a strong no-amnesty stand, famously calling for illegal immigrants to "self-deport." That may have helped Mr. Romney win the nomination, but he went on to garner just 27 percent of the Hispanic vote in the general election – a big reason for his loss to President Obama.
Rubio seems well aware of the potential pitfalls, and he has been careful to emphasize that he understands where those on the far right are coming from. He also isn't overpromising when it comes to what ultimately winds up in the bill (which has not yet been drafted), making clear that there's a chance he won't be able to support it in the end if, for example, adequate border-security triggers aren't included.
In an interview Tuesday with radio host Rush Limbaugh, Rubio said that if Mr. Obama tries to set off a "bidding war" by putting forward a proposal with more lenient provisions, "then there won't be a solution." He added: "I'm just trying to do the best I can with what's already a tough situation. I pray it works out. I can't guarantee that it will, but we're going to do our best."