Iowa Sen. Charles Grassley, the top Republican on the Senate finance committee, has emerged as one of the harshest critics of what the right likes to call “Obamacare.” After spending the first half of the year working with Democrats to find a bipartisan compromise, Grassley has spent the second half trying to prevent one.

He attacks the bill now being debated on the Senate floor as an indefensible new entitlement. He complains that it expands the deficit, threatens Medicare, and does too little to restrain health care inflation. At a town hall meeting in August, the 76-year-old Iowan played the age card. “There is some fear, because in the House bill, there is counseling for end of life. And from that standpoint, you have every right to fear,” he told an audience in John Wayne’s hometown of Winterset.

One might credit the sincerity, if not the validity, of such concerns were it not for an inconvenient bit of history. Not so long ago, when Republicans controlled the Senate, Grassley was the chief architect of a bill that actually did most of the bad things he now accuses the Democrats of wanting. As chairman of the finance committee, Grassley championed the legislation that created a prescription-drug benefit under Medicare. The contrast between what he and his colleagues said during that debate in 2003 and what they’re saying in 2009 exposes the disingenuousness of their current complaints.