By John Rondy
MILWAUKEE (Reuters) - Congresswoman Tammy Baldwin, one of the few openly gay members of Congress, announced on Tuesday that she will run for the Senate seat being vacated by retiring fellow Democrat Herb Kohl.
If elected to the Senate, she would be the first openly gay member of the upper chamber, according to Human Rights Campaign, the nation's largest gay an lesbian advocacy group.
But she is expected to face a tough contest in a sharply divided state, roiled by a partisan fight over a new law championed by Republicans stripping public sector unions of most collective bargaining rights.
Baldwin's district includes the state capital of Madison, where the largest demonstrations since the Vietnam War took place earlier this year to protest the union law. Baldwin participated in the demonstrations and spoke to the crowds.
Baldwin joins what is shaping up as a crowded field of aspirants for the seat including former Republican U.S. Representative Mark Neumann, who announced his candidacy last month, and Wisconsin Assembly Speaker Jeff Fitzgerald, a Republican who led the fight to curb union rights in the state Senate.
Also considering a run on the Republican side is former Wisconsin Governor and U.S. Health and Human Services Secretary Tommy Thompson.
Speculation is rife that Congressman Ron Kind, a member of the House of Representatives since 1996, will enter the race to challenge Baldwin for the Democratic nomination.
"The middle class is getting slammed and no one seems to be listening. Well, I'm listening," Baldwin said in a video message announcing her run sent to Wisconsin voters and supporters.
In the video, Baldwin touted her opposition to the 2003 Iraq War and to overturning the Glass-Steagall Act, a decades-old regulation that prohibited commercial banks from engaging in the investment business. Repeal of Glass-Steagall was cited by some critics of voiding the law as one cause of the 2008 financial crisis.
Baldwin became the first openly gay non-incumbent elected to the U.S. House of Representatives in 1998, according to the Human Rights Campaign, which endorsed Baldwin on Tuesday.
Democrats in 2010 lost a long-time U.S. Senate seat held by the party when former Democratic U.S. Senator Russ Feingold was beaten by Republican challenger Ron Johnson. Feingold decided to enter academia rather than try and regain his seat.
Kohl was elected to the Senate in 1988 and re-elected to a fourth term in 2006.
Neumann had lost a Republican gubernatorial primary last year against Wisconsin Governor Scott Walker. Neumann, a homebuilder, had unsuccessfully run against Feingold for senate in 1998.
Republicans need to gain just three U.S. Senate seats to take over majority control of the chamber in 2012.
(Reporting by Eric Johnson and James Kelleher; Editing by Greg McCune)