Jerry Taylor and Ramesh Ponnuru have been going a few rounds on the Medicare prescription drug benefit. The basic claims both are making are obviously true: The public wanted Medicare coverage of prescription drugs badly enough it was unlikely a political party could resist and still win at the ballot box; the enactment of the prescription drug benefit coupled with the failure of Social Security reform increased the unfunded liabilities of the major federal entitlement programs. Republicans have occasionally tried and failed to take positive steps on entitlements. They have also taken some negative steps and succeeded.

But Medicare Part D is a good example of how shortsighted the Republican approach to these issues can be. The prescription drug benefit didn’t change the long-term political calculus of which party held the advantage on health care and government spending on seniors, even if it yielded some short-term gains in 2002 and 2004. And while conservatives are deluding themselves when they pretend GOP fiscal irresponsibility was the main reason Republicans lost their majorities, GOP fiscal responsibility has undermined Republican arguments against Democratic spending.

It’s easy to see why Republicans made the Medicare Part D bet they did during George W. Bush’s first term. But it’s much harder to see how the party as a whole benefited over the long term. On health care and entitlements, Republicans too often seem to vacilate between ignoring political reality and being enslaved by it.