Yesterday, Governor John Kasich (R-OH), muscled home a Medicaid expansion over the disapproval of his own legislature. Meanwhile, Governor Chris Christie (R-NJ) relented on gay marriage in the Garden State by refraining from any more court appeals. Both of these decisions represent irreversible victories for the left. Irreversible victories are fundamentally different from ordinary victories, and they are especially powerful when the result has the blessing, however reluctant, of our political opposition.

As regular readers know, I have been kicking around the idea of shattering the Republican Party into two irreconcilable pieces by having the Democrats agree to join with moderate Republicans to elect a replacement for Speaker Boehner. I know that this seems like a pipe dream, but there is fresh evidence emerging every day that it has a kind of logical force that could make it a reality.

Consider Greg Sargent’s piece this morning that looks at the “epic damage” the Republicans did to themselves by shutting down the government and threatening our credit rating and the health of the global economy. After looking at the absolutely brutal poll numbers, Mr. Sargent asks:

The question, however, is: Do Republicans actually think it matters that their image is in such disastrous shape, or is that rendered inconsequential by the degree to which the House GOP majority is believed to be invulnerable?

There is a simple conundrum here. The Republicans who are most responsible for the government shutdown are the ones who are least vulnerable, and the ones who thought the shutdown was a terrible idea are the most vulnerable. Many lawmakers who thought their seats were safe are now looking at poll numbers that show them behind or even with generic Democrats. Not only are they angry with their more conservative colleagues for putting them in this situation, but they must be pretty desperate to avoid compounding the problem.

Their incentives are now much more closely-aligned with the incentives of John Kasich and Chris Christie than they are with the incentives of the conservative movement. If there is another government shutdown in January, they might not be able to recover. If there is anything they can do to dramatically improve their image, it is to help breakthrough the gridlock and make a demonstration of working with the president. Until recently, the only real pressure they felt was from a possible primary challenge from their right, but that calculus has now changed for dozens of House Republicans.

They can hope that the recent debacle has weakened the Tea Party faction and empowered Speaker Boehner (and Mitch McConnell) to make compromises, but there is little reason to believe that things will really improve between now and January.

Let’s look at two data points from the recent WP/ABC poll:

* Only 21 percent of Americans approve of the way the Congressional GOP is handling the federal budget, versus 77 percent who disapprove. Among independents: 20-78. Among moderates: 14-85. Among seniors: 18-79. Fewer than one in three regard the GOP favorably.

* Only 20 percent think Republicans are “interested in doing what’s best for the country,” while 77 percent think they’re “interested in what’s best for themselves politically.” Among independents: 14-83. Among moderates: 18-81. Among seniors: 24-74.

Now, as bad as those numbers are, imagine what they would be if you didn’t count the opinions of people in the Deep South. Imagine what those numbers look like if you only looked at people in New Jersey or the Philly suburbs or in Illinois, Ohio, Michigan, Iowa, and Wisconsin.

Can Republican lawmakers who represent districts outside of the Deep South survive this kind of public disapproval? I’d argue that they might survive it if they can repair some of the damage, but they can’t survive it if the damage is exacerbated and brought closer to election day. If these Republicans want to save themselves, they must make a break with the conservative movement, and they must make that break now.

For the Democrats, all they have to do is to make the offer and keep making it. Join with us and pass immigration reform. Join with us and pass a Farm Bill. Join with us and pass a balanced budget plan. Join with us and form a governing majority in the House that sidelines the Tea Party. They don’t have to agree to it, but refusing the offer will only serve to highlight the need to remove these folks from power.

It’s one more example where we can further the destruction of the modern GOP simply by being reasonable and offering them what they say they want. If they agree, the Tea Party is sidelined. If they don’t agree, the party gets wiped out. Either way, we win.