How Mitt Romney, Newt Gingrich, and Mike Huckabee are handling the issues that could sink their campaigns.

There was a kid who was 16 years old, he committed a burglary, it was aggravated, but not armed. And for that he got 108 years. … It was clearly a disproportionate sentence. … I'd love to tell you this isn't true, but that kid was black. And if he'd been white, and upper-middle class and had a good attorney, he wouldn't have served a day. He'd have had probation, he'd have gone to see a counselor, and he'd probably gone to college, and he'd probably be on Wall Street making a couple billion bucks a year. If I had the same file in front of me today that I had then, I would make the same decision.

Some liabilities are clearly insurmountable. That's why Sen. John Ensign, R-Nevada, decided on Monday not to seek re-election. His campaign was likely to be all about his extramarital affair with the wife of a top legislative staffer whom his parents then tried to pay off. Ensign allegedly tried to help his former staffer get a lobbying job. Had Marion Barry been in the same spot, he would have pitched the whole business as proof of his talents at community outreach and job creation.

Correction, March 8, 2011: This article originally and incorrectly stated that Marion Barry did not win re-election to mayor in 1994. He did and served from 1995 to 1999. (Return to the corrected sentence.)

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