Remember the Pentagon's $600 hammer? Its $1,000 toilet seat? Those 1983 revelations of profiligate defense spending touched off months of hearings and recriminations. Almost overlooked amid the hubbub was the man who started it all -- an unassuming Iowa farmer named Charles Ernest Grassley. Until the Pentagon follies, no one paid the junior senator from the Hawkeye State much notice. Nor did anyone have great expectations for this Republican who was labeled an Iowa bumpkin destined for a single term. But don't underestimate Grassley. Since acting on whistleblower complaints about defense spending 20 years ago, Grassley has taken on fraud...