One claim I’ve heard repeatedly from liberals during the health-care debate is that Republicans have no standing to complain about the dubious financing of Obamacare because the prescription-drug benefit they enacted in 2003 did not even attempt to pay for itself. (Jonathan Chait uses this argument to take a swipe at Michael Gerson today.) Now, if the Republicans are right that Obamacare will add to future deficits, the fact that they added to deficits in the past hardly invalidates their point.

But I think the context of the two debates also makes the comparison inapposite. A prescription-drug benefit was going to be enacted given its massive popularity. The Democrats had their own bill, which was twice as expensive and also unpaid for. Not passing the Republican bill would probably have led to even higher spending. An overhaul of the health-care system isn’t nearly as popular, and the Republicans aren’t pushing a twice-as-expensive alternative. Killing Obamacare will help keep deficits down–again, if the Republicans are right about the bill’s financing. If they’re wrong, on the other hand, then that’s the argument to use against them and the prescription-drug comparison is superfluous.

P.S. Great Gerson line: “Politicians claiming the idealism of saints have adopted the tactics of burglars.”