Heidi Heitkamp, a former North Dakota Democratic attorney general and tax commissioner, said Monday she is considering a run for the U.S. Senate, an office she previously declined to seek.

North Dakota Democrats have no declared candidate to succeed longtime Democratic incumbent Kent Conrad, who is stepping down next year. Freshman Rep. Rick Berg and Duane Sand, a Bismarck businessman, are competing for the Republican endorsement to run for Conrad's seat.

"I think that things are desperately wrong in Washington, D.C.," Heitkamp told The Associated Press on Monday. "I think that our Congress has lost touch with the people of this country, and that we need reasonable voices who will represent constituents, and not special interests."

Heitkamp, 55, said she would make her intentions public within 30 days. Former state Rep. Pam Gulleson, who had been promoted as a potential Democratic candidate, said last week she would run instead for the U.S. House seat now held by Berg.

Gulleson said Heitkamp wasn't a major factor in her decision.

Former Democratic Rep. Earl Pomeroy also has been mentioned as a Senate candidate, but he said he is not planning a campaign. Berg defeated Pomeroy last year.

A Senate bid would be Heitkamp's sixth statewide race. She lost a race for state auditor in 1984, but Gov. George Sinner appointed her as the state's tax commissioner in December 1986 after the incumbent, Conrad, was elected to the Senate. She won her own four-year term as tax commissioner two years later.

Heitkamp was elected attorney general in 1992 and re-elected four years later. She ran for governor in 2000 but lost to Republican John Hoeven, who is now a U.S. senator.

Democrats prodded Heitkamp to run against Hoeven again last year, when the Republican decided to seek the Senate seat being left open by retiring Democrat Byron Dorgan. She declined, saying a Washington office held much less interest for her than another campaign for governor in 2012.

But she said Monday that Conrad's decision to leave the Senate and Congress' "inability to compromise" on important issues have made her rethink the matter. Some issues important to North Dakota, from water management to farm aid, "really are, in many ways, federal issues," she said.

Heitkamp said she was not influenced by an August survey by a Democratic opinion pollster that concluded Berg may be vulnerable.

"I was considering this before any poll, and I am smart enough and have been around this business long enough not to put any reliance on early polling," she said.

Last month, Heitkamp praised state Sen. Ryan Taylor's announcement that he was considering a run for governor. She called Taylor, the North Dakota Senate's Democratic minority leader, a "dynamic and thoughtful leader" and said Democrats "would be lucky to have him as our nominee for governor."

Heitkamp has not sought public office since her loss to Hoeven, but she has remained active in Democratic politics and public issues.

She served as chairwoman of a successful 1998 ballot initiative campaign that required the Legislature to devote a larger share of its settlement with the nation's largest tobacco companies to North Dakota programs that discourage tobacco use. Heitkamp helped to negotiate the settlement when she was North Dakota's attorney general.