One thing my presidential election model can’t tell you is what sort of Congress the next president is likely to end up with. But we can speculate.

(Brian Snyder/Reuters)

If Obama wins the election, the odds are that he’s facing a Republican House, and perhaps even a Republican Senate. But it’s not a sure thing. Speaker John Boehner said he thinks Republicans have a 1-in-3 chance of losing the House. InTrade puts it a smidge closer to 1-in-4. But that’s assuming the full range of possible election outcomes. If the premise is that Obama is winning, Democrats have a slightly better chance of taking back the House, as that’s a scenario in which the election is definitely breaking their way.

Sidenote: InTrade gives Democrats a better shot at taking back the House than keeping the Senate. The reason is that Democrats are defending 23 seats, while Republicans are defending only 10. That’s because the 2012 Senate election is the follow-up to the 2006 Senate election, in which Democrats enjoyed an extraordinary wave. Now they’re left defending all those seats. So it’s entirely possible that Obama could win, the House could flip, but Mitch McConnell could become Senate Majority Leader.

Odds are, in other words, that if Obama wins, he will still be negotiating with Republican leaders in Congress. But the same can’t be said for Mitt Romney.

If Romney wins the election, it’s almost a sure bet that Republicans win control of both the House and the Senate. And that matters. Right now, the GOP’s agenda is the Ryan budget, and that’s entirely fiscal: It’s a premium support plan for Medicare, and tax cuts, and deep cuts to Medicaid, food stamps and other domestic programs. All that can be passed through budget reconciliation — which is to say, all that can be made immune to the filibuster.

So if Romney wins and the Republicans take control, they could accomplish quite a lot on party-line votes, even if their majorities are slim, and Democrats are opposed. Indeed, Romney could end up being a fairly transformational president for conservatives so long as he’s paired with a Republican Congress.