Why didn’t Republicans preempt President Barack Obama’s executive action on immigration with their own legislation? At the very least, that would have worsened the politics of Obama’s move. At best, it would have forced Obama to rethink taking unilateral action at all.

New York’s Jonathan Chait answered that question Wednesday, arguing that Republicans failed to recognize that their traditional legislative strategy—to block everything Obama opposes—would not work on the issue of immigration, since Obama had the legal authority to take unilateral action. “Republicans were stuck carrying out a strategy whose endgame would normally be ‘bill fails, public blames Obama’ that instead wound up ‘Obama acts unilaterally, claims credit, forces Republicans to take poisonous stance in opposition.’” Chait writes. “They had grown so accustomed to holding all the legislative leverage, they couldn’t adapt to a circumstance where they had none.”

I think Chait slightly overstates how poisonous the GOP position is. But let’s assume he’s right and Obama’s move is a huge political victory for the Democratic Party. I think there is a better reason why Republicans didn’t adjust their legislative strategy: This is actually the best political outcome for them.

To understand that, you have to look what legislation the House GOP would actually pass on immigration. The problem is Republicans cannot agree on what such legislation would look like. Last week, for example, the Washington Times published a special section on conservative immigration solutions, with contributions from Senator-elect Cory Gardner, Governor Susana Martinez, anti-tax zealot Grover Norquist, Representative Jason Chaffetz, right-wing heart throb Ben Carson and many others. In Ron Fournier-esque fashion, Martinez and Norquist sidestepped the question entirely, instead demanding that Washington show leadership. But the others tried to answer the question. Nearly all agreed on the need for stronger border security and an expansion of high-skilled immigration. But that leaves a big question unanswered: What would Republicans do with the 11 million undocumented immigrants living in the U.S. right now? Carson suggests a program where they could apply for guest worker status once they leave the country. Some undocumented immigrants might choose that option but millions wouldn’t. They'd remain here in the U.S., just like they are now, and Carson doesn’t say what how he would handle them. Gardner and Chaffetz ignore the issue entirely.

Their political dilemma here is pretty obvioius. They can’t endorse a path to citizenship, or even just legal status for undocumented persons, because the conservative base wouldn't tolerate it. Ideas that attempt to find some middle ground, like Carson’s proposal, don’t fully address the problem. What the base really wants is to deport almost everyone living in the U.S. illegally—something that's not possible, as a practical matter, and would be political suicide if somehow it did work. Even those Hispanics sympathetic to the Republican Party now would abandon it.