Tinklenberg, a centrist Democrat, ran against Bachmann last year in an open seat race -- and was the early favorite. But the more-liberal child safety advocate Patty Wetterling dropped her Senate bid and defeated him for the Democratic nomination. Bachmann then handily defeated Wetterling, 50-42%.
Tinklenberg initially opted not to run again for Congress, but after the collapse of the bridge in Minneapolis, he reconsidered given his background in transportation issues. He enters the race as a frontrunner, but will be facing attorneys Robert Hill and Bob Olson for the nomination.
Bachmann has drawn scathing fire from liberal activists over her outspoken conservative views, particularly on cultural issues. She also drew controversy when she held her arm around President Bush for 30 seconds after his State of the Union speech this year.
The exurban Minneapolis/St. Cloud district is still solidly conservative, giving President Bush 57 percent of the vote in 2004.