Ezra Klein notes that, if Romney wins, that means he’ll probably also deliver Republican majorities in both houses of Congress.

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.

Not only will Romney most probably have Congressional majorities to work with, he will have a real mandate to do precisely all the things liberals like Klein dread, to begin the reduction of the size and responsibilities of the entitlement state.