The revolving door between former members of Congress and lucrative lobbying firms usually leads one way. But Jim Slattery is trying to make a U-turn.

After spending more than a decade in Washington making millions of dollars at one of the nation’s most prestigious law firms, the former Democratic congressman from Topeka is jumping back into the political arena in a bid to unseat Sen. Pat Roberts, R-Kan.

Roberts’ campaign has already gone after Slattery with radio ads calling him a “Gucci loafers and all” lobbyist who’s out of touch with voters.

Slattery, who left Congress after getting trounced in the 1994 Kansas governor’s race, says he’s proud of his private sector work and claims he never lobbied for a position inconsistent with his record in the House. He says most of his income has come from working as a lawyer, not as a “big-time lobbyist.”

“I never took on a client or a cause that I did not believe in,” Slattery, 69, said in an interview.

More than 150 former members of Congress were registered as federal lobbyists last year, but it’s unusual for one to seek public office again. Recent scandals involving Jack Abramoff and former Rep. Randy “Duke” Cunningham make it especially tough for lobbyists to return to the campaign trail.

“Rightly or wrongly, lobbyists do not have a good reputation right now,” said Massie Ritsch, a spokesman for the Center for Responsive Politics, a nonpartisan research group. “Candidates running for office routinely criticize their opponents for being too cozy with lobbyists. When you actually have been a lobbyist, that can be an even greater political liability.”

At the same time he has come under criticism, Slattery noted that Roberts has benefited from more than $4 million in campaign contributions from special interests since he’s been in the Senate.

“One of the things that is amazing to me is these politicians that take money from all these special interests and all these lobbyists want to turn around and blast all the people that line up in front of their office every day,” Slattery said. “There’s a hypocrisy to this that’s a little bit breathtaking.”

Roberts campaign spokeswoman Ashley McManus claims there’s a difference: “Jim Slattery stopped working for Kansas so he could enrich himself working for special interests.”

During his 14 years at Wiley Rein, LLP, Slattery has registered as a lobbyist on behalf of more than three dozen corporations and interest groups ranging from the steel industry and utility companies to railroads and telecommunications firms. The list includes heavyweights like Nucor Steel, Verizon Wireless, Motorola Inc. and General Motors.

In March, when Slattery testified before a House Energy and Commerce subcommittee on energy and air quality, chairman Rick Boucher, D-Va., welcomed him as “a former colleague of ours and former member of this committee who served with distinction.” Slattery spoke on behalf of Nucor Steel and the U.S. steel industry in favor of climate change legislation that would penalize imports from countries with less stringent environmental rules.

Working for Wiley Rein has been a major financial boost to Slattery. In 2006, his firm earned profits per partner of $4.4 million _ tops among all U.S. law firms according to The American Lawyer magazine.

Most of that came from fees awarded to the firm in the settlement of a major patent case against the parent company of BlackBerry wireless devices. Slattery said he played a small role in the case, urging House lawmakers not to intervene with the U.S. Patent and Trademark Office.

“I went over and told some key members of Congress they had no business getting involved in a matter pending before the courts,” Slattery said.

While his attempt to jump back into politics is unusual, there have been other lawmakers-turned-lobbyists who have been able to make the transition. After narrowly losing the Missouri governor’s race in 2000, Republican Jim Talent left Congress to work as a lobbyist, then came back to win a Senate seat in 2002.

Brian Bilbray was a former California congressman-turned-lobbyist who came back in 2006 to win the seat vacated by Cunningham, who pleaded guilty to accepting bribes.

But Slattery’s time away from public life has lasted much longer _ he’s spent 14 years as a lawyer and lobbyist versus 12 served in Congress.

Ritsch said lobbyists who return to public service need to be clear about cutting their ties to the private interests they used to represent.

“The concern is the lobbyist who gets elected to Congress will continue to lobby for the interests he used to represent instead of lobbying for the people who elected him,” Ritsch said.

Slattery says there is no question he would be an advocate for Kansas voters. To address the issue, he plans this month to release a list of every client he’s ever had and the work he’s done.

“Just like everything, there are good lobbyists and there are bad lobbyists,” Slattery said. “The relevant question is what have you been lobbying for and how have you been lobbying.”