Among the many reasons that Americans hold the House of Representatives in low repute — at historically abysmal levels, in fact — is the blatantly partisan and ideological misconduct of so many committee chairs. Without any evident embarrassment these mighty politicians deny science, defy mathematics and dismiss every fact that contradicts their prejudices. But bad as these chairs tend to be, none is quite as flamboyantly awful as Rep. Darrell Issa, chairman of the Government Oversight Committee, a special investigative panel whose latest effort to conjure scandal from nothingness at the Internal Revenue Service would provoke his removal by a responsible leadership.

As we have pointed out repeatedly in these pages, and as testimony by the IRS inspector general has since confirmed, it is now clear that right-wing groups were not targeted for exceptional scrutiny. Moreover, there was no political motive in the agency’s treatment of the tea party and associated groups seeking tax exemption (in many cases illegitimately).

It is now equally obvious that the behavior of Issa himself, with his attempts to skew his committee’s investigation and conceal testimony that exonerated the agency, represents the most serious wrongdoing in the supposed “IRS scandal.” But this isn’t the first time that the California Republican, who happens to be the wealthiest man in Congress, has misused the broad powers of his chairmanship. Actually, that is all he does — as he demonstrated in equally opportunistic and amateurish examinations of both the Benghazi tragedy and the “Fast and Furious” affair.

Issa’s stewardship of the House Government Reform Committee has failed even by the standards of the Republican congressional leadership, which must have hoped that he would have collected some Obama administration scalps by now. He delayed the Fast and Furious probe solely to extend it into the election year, blustered against Attorney General Eric Holder and accomplished — nothing.

There is little hope that Speaker John Boehner, who has enough problems maintaining a semblance of authority and dignity, will question Issa’s fitness to chair this important committee. But still we are left wondering: What would become of Issa if he were subjected to the Republican style of investigation? What if the presumption of guilt, the preference for insinuation over evidence, the omission of exculpatory facts, and the promulgation of conspiratorial speculations that feature in all of Issa’s theatrical probes were applied to him?

As the richest member of Congress, Issa seems to enjoy the same veneer of respectability that great wealth has provided to many dubious figures. But his past includes several troubling encounters with law enforcement, from alleged car thefts to weapons offenses. So what would the public learn from an Issa-style investigation of Darrell Issa?

First, the committee chair would reveal the troubling findings about Issa, namely that he was arrested not once but twice for illegal weapons offenses. Worse yet, he would explain, Issa had been convicted the second time. Then he would release slightly redacted copies of court records on file in Cleveland Heights, Ohio, where Issa grew up, showing an arrest, charges of auto theft and carrying a concealed weapon only one month after his discharge from the Army in the winter of 1972. Those same records would also reveal that Issa and an older brother were both suspects in the theft of a “new red Maserati sports car” from an auto dealership and that Issa was eventually indicted for larceny.

And then the committee might leak a second, even more damaging set of records showing that Issa had been picked up several months later on another weapons charge in Michigan, where he attended college. Police arrested him for possession of an unregistered handgun, leading ultimately to his conviction.

What we might not learn — at least not until the facts were excavated by less partisan probers — is that Issa was only 19 years old at the time; that the first set of charges in Ohio was eventually dropped by prosecutors; and that the Michigan charge was a misdemeanor, punishable by a $100 fine — which young Issa paid.

Yet whatever Issa did as a foolish kid could be made to look quite sinister by a congressional committee chair like him, dedicated to trumping up minor irritations into major scandals. How fortunate he is that nobody in authority has ever misused the investigative power to smear him — and that those currently in authority over him have no appetite for reining in his abuses of that power.