When the scandal broke last summer over U.S. Sen. Larry Craig’s arrest in a Minneapolis airport, fellow senators strongly urged him to resign. Barring that, they threatened to conduct a public ethics investigation into his actions. But the Idaho Republican knew better. After all, the ethics committees in both houses of Congress sat on the sidelines as members were arrested and indicted in the Jack Abramoff lobbying scandal.

So, he called their bluff and said he would serve out the remainder of his term, which runs through the end of this year. One reason he offered was that he wanted to defend himself against ethics charges.

It looks like he can relax on that score, because there appears to be little to no progress by the Senate Ethics Committee, although the public can’t be certain because the panel has invoked the historic secrecy that comes with such cases. So much for that threat of going public with televised hearings.

A recent McClatchy news report notes: “No one with the committee has asked to speak with anyone connected with Craig’s arrest or asked for more information about it, said Patrick Hogan, a spokesman for the Minneapolis-St. Paul Airport. ‘I don’t know what they’re doing, but they have not contacted us.’ “

In a “progress” report in October, the Associated Press reported that nobody from the committee had contacted Craig’s office or the arresting police officer about information or possible testimony.

The Craig case highlights why Congress needs independent oversight on ethical matters. Republicans see hearings as an embarrassment for the party. Democrats are wary of being accused of gay-bashing and they worry about setting a precedent that could ensnare their own members some day.

Congress has trumpeted recent changes to lobbying rules that kick in this year, but if enforcement remains rare and secretive, the public won’t be impressed.

The Senate has declined to take up legislation that would strengthen accountability. The House is advancing a bill that would allow for an independent body to conduct ethics investigations, but the ultimate decisions on whether to proceed would remain with lawmakers. Plus, the bill doesn’t give this new Office of Congressional Ethics the subpoena power it would need to unearth the facts of a case.

Corruption in Congress was a major issue in the 2006 elections and it cost Republicans, who were in the majority at the time. Now, it’s Democrats who will have a lot explaining to do if ethics investigations remain ineffectual.