The United States is a nation of immigrants. But despite this common ground, no issue seems to divide Americans like immigration—specifically, illegal immigration and how to deal with it. Which is why the House Republican leadership’s decision to finally back immigration reform in principle is, as Joe Biden might say, a big f-ing deal. The announcement came at a GOP party retreat in Maryland late in the week. More than a trial balloon but less than legislation, the officially-issued outline front-loads border security and internal enforcement, with employment verification and visa tracking. A path to citizenship will be granted to the children of the 11.7 million illegal immigrants currently living in the shadows, but not to their parents—a crucial distinction with the Senate bill passed last year. The good news is that Speaker John Boehner has finally decided to do what’s in the long-term best interest of his party and his country, betting big on what could be his most lasting positive legacy. “This problem’s been around for at least the last 15 years. It’s been turned into a political football. I think it’s unfair,” said the consummate dealmaker Boehner. “I think it’s time to deal with it. But how we deal with it is going to be critically important.” The bad news is that the Tea Party and associated right-wing activist groups have already declared immigration reform a betrayal of conservative virtue, shots fired in the GOP civil war. A “Death Warrant for Conservatism,” declared the Powerline blog, while Heritage Action’s Dan Holler told The Daily Beast’s Patricia Murphy the proposal amounted to “a full-throated embrace of amnesty.” The word “amnesty” has talismanic importance inside the arcane world of the conservagencia, with its whiff of Carter-era weakness and lack of accountability. This was the mantra right wing talk radio used to derail the Bush-backed bipartisan McCain-Kennedy immigration reform bill in 2007, and it elicits a predictably Pavlovian response among the rank-and-file. Specific facts no longer need apply. The problem with this play-to-the-white-conservative-populist-base impulse is that it ignores demographic and economic reality. Showing a callous lack of concern for the country’s largest and fastest growing minority group—Hispanics—is a slow form of political suicide, the most recent symptom of which was Mitt Romney getting just 27 percent of the Hispanic vote after calling for “self-deportation” while simultaneously criticizing President Obama for not passing immigration reform that Romney opposed when first running for president. So the House GOP leadership deserves real credit for finally getting the cojones to back immigration reform. But their renewed political courage doesn’t mean that they’ll take the New Year momentum and translate it into an immediate push for passage. Instead, the strategy seems to be to wait until the intra-party Republican primaries are over by early summer. From Senate Minority Leader Mitch McConnell to many GOP members of congress (who are decried as Republicans-in-Name-Only by an activist class who complains that they only have a 75 percent conservative rating), the primaries are a time of high political risk.Despite the rigged system of redistricting and state-by-state polarization that conspires to create an unprecedented number of safe seats, incumbents stand the greatest chance of losing power in a low-turnout primary election, where they might be accused of being insufficiently conservative. And despite Tea Party support falling to new lows in national opinion polls, in primary elections they can still be a force to fear—one consequence of which is the further delay and possible derailment of immigration reform. This is the Tea Party tail wagging the national policy dog. After all, the closer we get to November’s midterm elections, the more difficult it is to pass major legislation because politicos become more preoccupied with fighting than fixing. Immigration reform is a hugely consequential microcosm of the national political debate. Responsible Republicans realize they have an obligation to propose rather than just oppose. But the increasingly isolated conservative populist base is pre-occupied with resisting cultural change and while 82 percent of Tea Partiers see illegal immigration as a serious problem that doesn’t lead logically to support for reality-based proposals that seek to solve the problem. No wonder so many politicians see more upside in demagogue-ing the issue than dealing with it. What’s changed is that Boehner and other members of the Republican leadership increasingly recognize that they—and the country—cannot be held hostage by the impractical ideological fervor of 50 or so House radicals and their enablers among the fundraising-racket activist class. The choice is between governing and grandstanding, leaving a constructive legacy that will lead to long-term political gains or giving in to the fetid heat of those folks who would ruin if they cannot rule.