Thaddeus McCotter, a guitar-playing Michigan congressman with an independent streak, formally launched a longshot bid for the 2012 Republican presidential nomination Saturday.

The conservative McCotter made his formal announcement at an Independence Day rock festival outside Detroit. He filed the paperwork Friday to enter the Republican race for the right to challenge Democratic President Barack Obama.

McCotter, 45, is a rock fan known to quote song lyrics and at times challenge his party leaders. He enters the campaign as a heavy underdog with little name recognition or money.

The five-term congressman from the Detroit suburbs is a strong supporter of the car industry and backed the industry bailout, but he has appealed to tea party conservatives with calls for a fundamental restructuring of government.

McCotter said Friday there was room for more candidates in the Republican race, which is now led by former Massachusetts governor Mitt Romney and U.S. Rep. Michele Bachmann of Minnesota.

“I want to take my message out and . . . see if people respond to it,” he said in an interview with a Detroit radio station.