Sen. Marco Rubio, the Tea Party favorite from Florida, has become the face of comprehensive immigration reform, embarking on a frenetic media tour in recent days to sell a bipartisan plan to skeptical conservatives. Rubio has gone into the dragon's lair of right-wing radio three times in the past week — meeting with Rush Limbaugh, Sean Hannity, and Mark Levin — and emerged largely unscathed, fueling hopes that Congress could pass a plan that would offer a pathway to citizenship for the 11 million undocumented workers living in the United States.

Those hopes are shared not only by many Democrats, Latinos, and pro-reform groups, but Republican leaders who are eager to make their party more appealing to one of the country's fastest-growing demographics. However, there have recently been signs of discontent among some conservative stalwarts, a reminder of just how passionately members of the GOP base oppose offering "amnesty" to those who entered the country illegally. And if the base revolts against the bipartisan plan, no politician stands to lose more than Rubio, whose neck is so stuck out on the issue that it may be impossible for him to backtrack.

The editorial board of National Review, for example, came out strongly against the plan, and criticized Rubio in particular.

Each of the proposals contains an amnesty for the dozen million or so illegals already in the country, and none of them contains adequate security provisions. Panicked Republicans are looking for a grand bargain, but they are wrong on both the politics and the policy…

Senator Rubio, an exemplary conservative leader, is correct that our immigration system is broken. And he is correct that, at some point, we are going to have to do something about the millions of illegals already here. But he is wrong about how to go about repairing our immigration system, and wrong to think that an amnesty-and-enforcement bill at this time will end up being anything other than the unbuttered side of a half-a-loaf deal. And there is no reason to make a bad deal for fear of losing a Latino vote Republicans never had. [National Review]

National Review's editor, Rich Lowry, also panned the plan in a Politico op-ed titled "Marco Rubio's bad deal":

It's never a good sign when lawmakers can't call things by their real names. Even conservative star Marco Rubio — the gang's most important member, who has been energetic and fearless in making his case — calls illegal immigrants "undocumented" workers. He referred to them in a recent blog post as people "living in the United States without proper immigration documents."

Supporters of comprehensive immigration reform also resolutely refuse to say the word "amnesty." They contend that the proposed package is not an amnesty because illegal immigrants have to go to the back of the line for a green card. But before that happens, they get "probationary legal status" after passing a background check and paying a fine and back taxes. As a practical matter, this is the amnesty. [Politico]

Erick Erickson, the influential editor of Red State, had this to say, in a blog post called "I don't like Marco Rubio's plan":

The GOP was smart to put Marco Rubio as the face of the plan because many of us like him personally, support him still, and consequently don't want to seem critical.

But the plan makes the actual problem of immigration more difficult to solve. [Red State]

Ann Coulter at Townhall says:

Rubio's bill is nothing but amnesty. It isn't even "amnesty thinly disguised as border enforcement." This is a wolf in wolf's clothing. [Townhall]

And so on — the criticism from the right is just beginning. Which means Rubio, an early frontrunner for the 2016 presidential nomination, will have a difficult time navigating the debate without dinging up his knight-in-shining-armor image. It's worth remembering that John McCain's 2008 nomination was nearly scuttled over his so-called support for amnesty, a lesson that his successor, Mitt Romney, took to heart so deeply that he advocated a policy of self-deportation. 

"This is going to be tough for Republicans and the recidivist elements in our party," Alex Castellanos, a GOP strategist, recently told The Washington Post. "It will be all fine until there is a GOP primary, say for president, and one candidate breaks out as the anti-immigration candidate and appeals to GOP fears and not hopes."