Bernard Kerik’s problems go much deeper than not paying taxes for a nanny.

Kerik, who had been nominated to become the next secretary of the Department of Homeland Security, withdrew from consideration Friday. Kerik has also been dogged by accusations of abuse of power, reports of extramarital affairs and connections to shady characters, who have been accused of having ties to organized crime.

Kerik has a great biography, minus the details that cost him a spot in President Bush’s Cabinet. He rose through the ranks of the New York criminal justice system to become police commissioner, overcoming a difficult childhood. He also offered a unique perspective to the job at Homeland Security.

His questionable activities, however, sank any chance he had.

Kerik employed a nanny-housekeeper who might have been an illegal alien. He failed to pay taxes for the worker, and then didn’t tell the administration when it was considering him for the post. How, then, could Kerik properly oversee the agencies responsible for enforcing the country’s immigration laws if he failed to follow them?

According to the New York Daily News, Kerik also had a long-term affair with a corrections officer during the time that he ran the department. Both cases illustrate a shocking lack of judgment.

Infidelity does not necessarily disqualify someone from high-level public service. But in the case of one documented affair, Kerik’s misdeeds might have gone beyond cheating on his wife. Two lawsuits, filed by other corrections employees, claim that Kerik retaliated for any slight against his mistress, abusing his authority, and that he protected her from poor performance reviews.

The Daily News also reported that an investigation of Kerik showed he had accepted money and gifts without filing the appropriate disclosures and had ties to “a construction company that investigators believe is linked to the mob.”

And Newsweek reported that an arrest warrant was issued for Kerik in 1998 in connection with lawsuits over unpaid bills.

After withdrawing his nomination, Kerik said Saturday that he wanted to avoid a confirmation process that would be embarrassing to the president. It’s too late to put that genie back in the bottle. The explosion of his nomination is an embarrassment to the president and the people who have supported Kerik, including former New York Mayor Rudy Giuliani, who appointed Kerik as police commissioner and more recently has been a business partner with him.

Kerik was commissioner of police on Sept. 11, 2001. That experience, and his work on the front lines as a beat cop, would have been a welcome addition to the Bush Cabinet. Perhaps he could have reformed the way the Department of Homeland Security spends its money, putting a larger emphasis on locations that face the greatest threat from terrorism.

Nonetheless, it was not enough to overcome his questionable financial dealings, disregard for immigration and tax law, and poor judgment. He turned out to be a poor choice to lead the Department of Homeland Security. He was right to withdraw.