Marco Rubio is a celebrity senator as well as a Cuban-American, and he's been engaged in an entertaining series of flip-flops on the question of comprehensive immigration reform that have captivated D.C. political reporters. But today's zig toward skepticism no more makes immigration reform doomed than last week's zags made it a sure thing. The core issue remains what it's long been—do House Republicans want to allow a comprehensive immigration reform bill to pass or don't they?
This is a slightly separate question from whether they want to vote for such a bill. Obviously some House Republicans have to vote for an immigration bill for it to pass. But not all that many. What does have to happen for an immigration bill to pass is that it has to come to the floor of the House of Representatives. And that's at the discretion of John Boehner, who is answerable first and foremost to his caucus. If his caucus has the sense that letting a bill go through is in its interest, then a bill has a fighting chance. If his caucus doesn't, then a bill doesn't.
And to be honest, it's a bit hard to see why the caucus would.
From the GOP perspective, the calculus of a path to citizenship has two elements. On the one hand, most of these new citizens would probably be Democrats. On the other hand, taking part in a bipartisan immigration reform effort might open Latino voters' ears to other aspects of the GOP message. But the absolute worst-case scenario is one in which a path to citzenship becomes law over the loud objections of GOP-elected officials. In fact, the best case for Republicans is the opposite—they vote for a bill, but Democrats kill it for some reason. Yet it's hard to see why that would happen. So basically this comes down to the hearts and minds of House Republicans. Do they think a path to citizenship for unauthorized immigrants is a good idea? Do they think there's some other aspect of immigration reform that's so valuable they want to trade it for a path to citizenship they dislike? If the answers are "no" and "no," then it's dead whatever Rubio does.