I was just thinking about this the other day. It’s entirely academic, but what if John Boehner called up Barack Obama today and said, let’s talk. This sequester is no good, let’s work something better out. So there are a couple days of furious negotiating, culminating in a $2.5 trillion replacement that raises the Medicare age and does the COLA adjustment to Social Security that have been bandied about, and consists of around $800 billion of revenue, including caps on deductions and the closing of various “loopholes” in the tax code. Let’s just assume this could somehow happen, and that Boehner (and Mitch McConnell) could pledge half their caucuses to voting for it. What would the effects of this be politically?

The most obvious one would be that it would be politically great for Barack Obama. Obama’s ambition is to enact as much big change as possible to solve problems, so this would be quite satisfying to him, no doubt. It would make him a hero of the constellation of corporate and wealthy people who are aligned with Pete Peterson, which is not a bad thing for someone who’s going to need to raise tens of millions of dollars right after leaving office to build a presidential library and isn’t likely to get it from college students writing fifteen dollar checks every month. It would be a big-time legacy burnisher, and in policy terms it would (if actually allowed to be implemented) cut deficits significantly over a decade. All upside for him, really.

On the other hand, it would be politically disastrous for Democrats. I can think of nothing better that would open up the cleavages between those perpetually uncomfortable bedfellows, the New Democrat corporate types who are there mostly for social issues and the left-liberals, who are there for everything. Neither group much likes the other, and a grand bargain would run the risk of causing enormous disunity, especially if rejecting the deal becomes a litmus test to those interests. And it’s hard to see a reason why it shouldn’t. Second-term presidents, the cliche goes, take bigger chances and entertain ideologically unorthodox options because they see the end coming. But it’s also common that those options don’t work out, and second-term rebellions are quite common since the risk of losing favor with a lame duck administration are much lower than against a first-term team that will have the better part of a decade to go. Putting yourself out there for a potential primary challenge is a whole different story. So you have George W. Bush suffering virtually no first-term rebellions, and then having at least four major ones in his second (Social Security, immigration, Harriet Miers and the first attempt to pass TARP–am I missing one?). And then there was St. Ronaldus Magnus, who spend his last two years getting kicked in the teeth by Jim Wright, having veto after veto overridden as Republicans in Congress chose to focus more on their problems than his.

Which would all be well and good, only the timing could make the 2016 elections very tricky. Assuming that Hillary opts out, it’s easy to imagine someone like Andrew Cuomo strongly supporting the deal and getting enormous financial backing from the DLC types, and perhaps Elizabeth Warren strongly opposing the deal and rallying Democrats behind that position and her candidacy. Given the makeup of Democratic primary electorates, it’s easy to imagine her being successful, but it’s harder to imagine any candidate who would be able to pick up the pieces and run a united general election campaign (perhaps leading to an absurd spectacle like Warren/Bayh ’16!). And the next election is going to be pivotal to American liberalism–preserving the Affordable Care Act, for one, and also ensuring that Scalia and Kennedy get replaced by better judges (it seems unlikely that both will be serving on the court in twelve years, as both would be pushing 90). You wouldn’t want to contest the election in an environment where large blocs of your party are at each others’ throats.

But ultimately, this would come down to whether or not the bill would actually pass in this scenario. My guess is that it would pass in the House–sure, the 71 members of the Congressional Progressive Caucus would almost certainly be against it, but beyond that, it’s difficult to say where the rest of the “no” votes would come from. The Senate would be a lot easier: given that there’s a baseline of 20-25 “no” votes from the GOP on any deal with Obama there, they’d really only have to produce enough to get to 41 to filibuster it. (I’m assuming the vast majority of Democrats will vote for it, because that’s just what they do.) The Bernie Sanders-Al Franken-Elizabeth Warren-Tammy Baldwin cohort would be able to get close just on their own, there probably are enough other anti-catfood Dems to block cloture. Which would be such a perfect metaphor for the entire Obama era, the hard-right inadvertently saving us from harsh spending cuts, and using the filibuster to do it.