The Christian Science Monitor examines the different treatment in the GOP Senate caucus for Senator Larry Craig when compared to the scandals involving David Vitter and Ted Stevens. Melanie Sloan explains it succinctly:

Sen. David Vitter (R) of Louisiana was applauded by his Republican colleagues when he returned to a caucus meeting after admitting he made phone calls to a prostitute service. Sen. Ted Stevens (R) of Alaska, whose home was recently searched in a federal corruption investigation, appealed to his colleagues to wait until the probe was complete before rushing to judgment – and his colleagues on both sides of the aisle have respected that request.

Attempting to draw a bright line explaining such differences, Senate Republican leader Mitch McConnell told reporters this week that the difference is that Craig pleaded guilty, while Senator Stevens is still under investigation and Senator Vitter has not been charged with a crime.

A leading ethics watchdog group calls that standard disingenuous. "It's a very fine point to say that one person pleaded guilty to a low-level sexual misconduct crime and another didn't get charged, when both have admitted to crimes," says Melanie Sloan, executive director for Citizens for Responsibility and Ethics in Washington.

"Just because [Vitter's] conduct seemed to be too long ago to get charged, the underlying conduct is the same. We're just talking about the venue in which they admitted it," she adds.