On the other hand, if the bill fails – or if it passes but winds up simply granting legal status to people here illegally without following through on the promise to secure the border – Rubio may find some of those same bridges burned. He would then face the delicate task of having to repair relations with the party's base, for whom illegal immigration has often proved a key voting issue in primaries.
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.