Barack Obama’s jobs bill is getting a new shot of energy today as Senate Democrats rolled out a millionaire’s surtax to finance it. Early reporting suggests that the very popular idea may be enough to unify Senate Democrats, even while making it even less likely that tax-phobic Republicans will drop their opposition. Republicans might say that the Democrats are playing politics by pushing things they know will never pass. And Republicans would be right. But Democrats should play politics in this manner — it’s in their interests to do so. And Republicans are the ones who pushed Dems in this direction in the first place.

I think there are three lessons so far from the jobs bill saga.

The first is that taking the fight to the voters really doesn’t do much good up on Capitol Hill. As Greg reported earlier, Obama has managed to move the dial on jobs a bit in his direction. But that just isn’t going to matter for Republicans, and doesn’t even seem to be enough to necessarily secure support from moderate Democrats. It’s simply very difficult for presidents to override the preferences of Members of Congress.

The second is that much of what you heard in 2009-2010 about Obama erring by “letting” Congress take the lead in writing key legislation was mostly nonsense. The bottom line is that Congress always winds up writing legislation — just as Senate Democrats are re-writing Obama’s jobs plan this time around.

And the third is that while the best plan for Obama would be to find some way to actually improve the economy, as long as Republicans are going to block everything that Obama (and economic conventional wisdom) believes will work, then Obama and the Democrats are free to propose whatever polls well. So they might as well do just that. The American Jobs Act, now modified by Senate Democrats, is a start at that; I’d expect that we’ll see a lot more next year.

Put that all together, and it appears the incentives created by Republicans are for the Democrats to play politics on jobs as much as possible. That wouldn’t be the case if Republicans had their own legislative goals and were willing to compromise to get them passed, but that’s clearly not the case; Republicans have instead attempted to get what they can through brinkmanship and blackmail, and pretty much ignore governing the rest of the time. Compared to that, a little playing to the vast majority of the American people who like soak-the-rich rhetoric is hardly unfair politics at all.