Yglesias has an excellent reminder not to get too excited about long-term budget plans.  We have a long-term problem and the obvious solution is a long-term plan.  But the obvious solution is wrong.  Nothing Congress does today will determine what the budget is in 2031, because Congress can override that in 2021-2030.

That’s part of why Ryan’s plan is such a cheat: it hands $3 trillion in cuts to the rich right now, to be paid for by vague spending cuts ten years down the road.  Seriously, you’re a Congressman in 2031 and seniors are howling about Ryan’s benefit cuts: you’re going to be constrained by Ryan-from-20-years-ago?  Certainly not, any more than Ryan feels constrained by anything Congress did in 1991.

This isn’t speculation, it’s just history.  We had a balanced budget in 2000, carefully established after years of work by Clinton and his congressional allies.  It was destroyed in a few short years by his successor.

The paradox is that if Congress does nothing, then we actually come close to a balanced budget.  Bush’s deficit-pumping tax cuts are scheduled to expire in 2012; we’re leaving Iraq; there are other things like the ‘doc fix’ that would expire if Congress didn’t act.  Doing nothing is not the best plan; the irony is that it’s better than what is likely to actually get enacted, because the Republicans are going to insist on worsening the deficit with tax cuts.