Rep. Mark Souder, a Republican from Indiana who looks like Radar O’Reilly from M*A*S*H*, has just introduced a bill with the noble goal of preventing another Duke Cunningham.

Souder wants members of Congress, federal candidates, and top admininstration officials to disclose the mortgages they hold on their castles, mansions, compounds, and beach homes. “Transparency,” Souder says, “is fundamental to public trust.”

He took the first step by disclosing that he has eight years left on his mortgage, owes $75,000 and is paying 6.875 percent interest.

As insanely greedy as Duke was, even he would have thought twice before listing that he owed $0 on a $2.55 million mansion he had bought the previous year. But what prompted this wasn’t Duke, but the low-cost loans two senators got from the “Friends of Angelo” program. Souder and Rep. Darrell Issa, R-Vista, one of the wealthiest representatives, are calling for a House investigation.

It’s a good first step, but the bill doesn’t go far enough. A survey by Politco.com found more than one of four senators have no mortgages.

How about requiring members of Congress to disclose the values of their homes?