The rebel­lion of Wis­con­sin pub­lic employ­ee union­ists against Gov. Scott Walker’s plan to take away col­lec­tive bar­gain­ing rights gen­er­at­ed crowds of 100,000 peo­ple or more at the state capi­tol in Madi­son. One of the most artic­u­late and pop­u­lar voic­es for the work­ers’ cause proved to be U.S. Rep. Tam­my Bald­win, a sev­en-term vet­er­an of the U.S. House of Representatives.

With a combination of intellect, political principles and personal warmth, Baldwin has developed an enthusiastic base of constituents in her district and among gays and lesbians nationally.

Bald­win, 49, has launched a pop­ulist cam­paign for the U.S. Sen­ate, seek­ing to replace the retir­ing Herb Kohl, a mild­ly lib­er­al Demo­c­ra­t­ic sen­a­tor who has served since 1988 (Wisconsin’s oth­er Sen­ate seat is held by for­mer CEO Ron John­son, who beat pro­gres­sive stal­wart Russ Fein­gold amid the Demo­c­ra­t­ic car­nage of the 2010 midterm elections).

With her com­bi­na­tion of intel­lect, polit­i­cal prin­ci­ples and per­son­al warmth, Bald­win – the nation’s first open­ly gay per­son to run for the U.S. Sen­ate from either major par­ty – has devel­oped an enthu­si­as­tic base of con­stituents in her dis­trict, and among gays and les­bians nation­al­ly. Born in Madi­son, she has been open about her sex­u­al­i­ty since win­ning a seat on the Dane Coun­ty Board in 1986.

Despite her open­ly left pol­i­tics, Bald­win is well liked by politi­cians of both par­ties. While serv­ing in the state Assem­bly from 1993 to 1999, when she was elect­ed to Con­gress, she even got along well with then-leg­is­la­tor Scott Walk­er (now the state’s gov­er­nor), with whom she worked close­ly on a law to require dis­clo­sure of cam­paign funding.

The grow­ing shift in the nation­al mood makes this an ide­al moment for Baldwin’s mes­sage, says David New­by, retired pres­i­dent of the Wis­con­sin State AFL-CIO and her campaign’s trea­sur­er. ​“The Wis­con­sin rebel­lion and Occu­py Wall Street move­ments have been rais­ing issues of eco­nom­ic injus­tice and work­ers rights,” New­by says.

Jim Cavanaugh, pres­i­dent of the South Cen­tral Fed­er­a­tion of Labor, says that Bald­win has tak­en the most pro­gres­sive posi­tion on every major issue dur­ing her tenure in the House. ​“She’s con­sis­tent­ly been … an out­spo­ken advo­cate of [a] sin­gle-pay­er [health­care sys­tem]. She vot­ed against going to war in Iraq. She has opposed free-trade agree­ments, includ­ing those with Colom­bia, Korea and Pana­ma, which passed with the bless­ings of Pres­i­dent Obama.”

Adding to the insur­gent tide is a like­ly recall elec­tion some­time next spring for Gov. Walk­er, whose approval rat­ing has plum­met­ed since he began attack­ing pub­lic employ­ees. On Novem­ber 15, the Demo­c­ra­t­ic Par­ty and a group called Unit­ed Wis­con­sin began gath­er­ing the 540,000 sig­na­tures need­ed to trig­ger a recall vote.

Baldwin’s Repub­li­can oppo­nent remains unclear. The heavy­weight in the GOP crowd is for­mer Gov. Tom­my Thomp­son, who was elect­ed four times by mod­er­at­ing his pre­vi­ous hard-right posi­tions. Thomp­son has had a neg­li­gi­ble pres­ence in the state since 2001, when he began serv­ing as George W. Bush’s Health and Human Ser­vices sec­re­tary. Thomp­son now works for a pow­er­ful law and lob­by­ing firm, feed­ing the per­cep­tion of him as an insider.

The Club for Growth, which favors the for­mer con­gress­man Mark Neu­mann, spon­sored TV ads attack­ing Thomp­son for being too mod­er­ate (he advo­cat­ed health­care reform while in the Bush administration).

Labor attor­ney and Fight​ing​Bob​.com blog­ger Ed Gar­vey believes that Bald­win has the mes­sage and the per­son­al skills to attract vot­ers. ​“Tam­my offers what Wis­con­sin pro­duced for so many years in peo­ple in the Sen. Gay­lord Nelson/​Bob Kas­ten­maier mold – no one ques­tions her integrity.”