The investigation led by Rep. Dan Burton of Indiana into the pardons issued by Bill Clinton at first looked like a vehicle merely to further embarrass the former president. Now, with the news that Mr. Clinton’s brother-in-law, Hugh Rodham, was offered $400,000 to successfully lobby for a pardon and prison commutation, the investigation seems like the only prudent action to take.

At the request of the Clintons, Mr. Rodham has returned the money Almon Glenn Braswell, a businessman convicted of mail fraud and perjury in 1983 and Carlos Vignali, currently in prison for cocaine trafficking, sent for his lobbying efforts. Both the former president and Sen. Clinton claimed not to have known of the arrangement that Mr. Rodham, a Miami lawyer, had with the pair. As with a multitude of examples of atrocious behavior as they prepared to leave the White House, their denial is hard to believe.

Rep. Burton’s committee is expected to reconvene next week, when it will ask Clinton aides about the pardon of the now-notorious Marc Rich. The committee could quickly review all pardons issued by the former president, select those opposed or unsupported by the Justice Department and review their propriety. House investigations of Mr. Clinton nearly achieved permanent committee standing over the last eight years, and a few lawmakers abused their authority in dragging out or inflating minor missteps. Those lawmakers sometimes found an unhappy electorate at home and no longer are in Congress. But in this case, representatives have both a serious issue and an interested public more than dismayed by Mr. Clinton’s action.

The former president tried to defend his decision in the Rich case in an op-ed piece in last Sunday’s New York Times. One of the most remarkable aspects of the 1,700-word piece was how few supporters it found. Normally understanding and loyal Democrats declared themselves repulsed by the pardons and further disgusted by Mr. Clinton’s attempt to explain them. A close reading of the commentary, said one of Maine’s leading Democrats, showed the former president grasping at any excuse to justify his decision.

Mr. Clinton’s pardon of Mr. Braswell already had federal prosecutors angry because Mr. Braswell was under further investigation for money laundering and tax evasion. Mr. Clinton claims not to have known about the current investigation. For a man who prided himself for knowing mind-numbing details of every policy decision he made, this sudden lack of knowledge about who was being paid to protect whom against prosecution is impossible to accept.

Rep. Burton’s committee might help review these and other important details that Mr. Clinton claims not to know.