Ever since John Boehner failed to round up a majority in support of the GOP version of farm bill reauthorization, there's been some interest in the implications of this for comprehensive immigration legislation. Most of all, I think there just aren't many implications—they are different issues with different coalitions. But the farm fail does underscore that the strategically savviest path for Boehner to block comprehensive immigration reform probably isn't available.
That's because the best way for Boehner to prevent a comprehensive deal from happening is to pass an immigration reform bill that takes large sections of the Gang of 8 bill but just leaves out the main amnesty and path to citizenship that's at the core of Democratic Party immigration politics.
If a bill like that passes the House, you'll have an old-fashioned legislative standoff. Republicans would be able to say that all sorts of stuff for high-tech workers and agricultural labor and border security that Democrats claim to favor is being held up over their demand for amnesty. Then Democrats could counter that all this stuff is actually being held up by Republican obsession with "self-deportation." But the gridlock dynamic would be stable, and even Senate Republicans inclined to vote for the Gang of 8 bill might also be declined to defend the House bill as a reasonable measure and call on Democrats to compromise.
But this strategy requires exactly what the right-wing of Boehner's caucus has repeatedly failed to deliver—a little bit of tactical flexibility.
Absent tactical flexibility, Boehner's alternative to allowing the Gang of 8 bill to pass mostly on the back of Democratic votes is to simply pass nothing. Procedurally speaking, if mainstream House conservatives want to hold that line, nobody can stop them. But refusing to let a bipartisan bill come to the floor is a tougher sell politically if there is no all-Republican alternative bill that can command a majority. That's why Boehner has tried over and over again to pass all-Republican bills that can't possibly pass the House. The failure of the farm bill—like the failure of the "Plan B" tax bill before it—is a reminder that this option probably isn't available.