Lesbian Rep. Tammy Baldwin has won her race for the U.S. Senate from Wisconsin in a historic first for the LGBT community. She becomes the first openly gay person to serve in the Senate.

With 77 percent of precincts reporting, Baldwin was leading former Wisconsin Gov. Tommy Thompson, 51-46 percent.

“I am honored, and humbled, and grateful,” Baldwin said in election night remarks. ” And I am ready to get to work.  Ready to stand with President Barack Obama.  Ready to fight for Wisconsin’s middle class!”

Early polls showed Thompson with a slight lead over Baldwin shortly after Thompson won the GOP nomination in a primary in August. By the middle of September, polls showed Baldwin in the lead, but the size of her lead narrowed by late October, with some pollsters saying the two candidates were in a statistical tie going into Tuesday’s election.

Baldwin’s quest to become the nation’s first openly gay U.S. senator captured the attention of the LGBT people across the country, many of whom contributed money to Baldwin’s campaign.

She also received backing from the Democratic Senatorial Campaign Committee and other Democratic leaning groups, including labor unions and environmental organizations.

In 1998, Baldwin became the first openly gay non-incumbent to win election to the U.S. House when she won her race for Wisconsin’s Second Congressional District in which the state capital of Madison is located.

In her seven terms in Congress, Baldwin became known as one of the strongest advocates of LGBT rights in the House as well as one of the strongest champions of progressive causes and policies.

Thompson, whose supporters describe him as a moderate, served as governor of Wisconsin between 1987 and 2001. He served as Secretary of the U.S. Department of Health and Human Services in the Bush administration from 2001 to 2005.  He became a candidate for the Republican presidential nomination in 2008 but dropped out of the race before the start of the primaries.

Thompson has said he personally opposes same-sex marriage and supports the Defense of Marriage Act, which defines marriage under federal law as a union only between a man and a woman. But he has said he doesn’t favor a constitutional amendment to ban marriage equality and favors leaving same-sex marriage decisions to the states.

He has said he opposes workplace discrimination based on someone’s sexual orientation but has not said whether he would support federal legislation to ban anti-LGBT discrimination in the workplace.

Although Wisconsin members of the gay Republican group Log Cabin Republicans are supporting Thompson, the national Log Cabin organization, which endorsed GOP presidential candidate Mitt Romney for president, didn’t endorse Thompson.

“We endorsed candidates that engaged with us and asked for our endorsement,” said Log Cabin president R. Clarke Cooper, who noted that the group endorsed just four U.S. Senate candidates this year.

The outcome of Tuesday’s Senate election in Wisconsin marked the end of a bruising campaign, which the Milwaukee Journal Sentinel says may have broken a national record for the most negative TV ads of any U.S. Senate campaign in the state and possibly in the nation.

The Journal Sentinel reports that both Baldwin and Thompson appear to have lashed out at each other with equal force, with some independent observers saying some of the ads from both sides included misleading information.

None of the Thompson attack ads appear to have singled out Baldwin based on her sexual orientation.

However, in at least one instance, a Thompson campaign official sent an email to the news media in early September, one day before Baldwin spoke before the Democratic National Convention in Charlotte, N.C., highlighting Baldwin’s appearance at an LGBT Pride festival in Madison several years earlier.

The email, sent by Thompson campaign staffer Brian Nemoir, included an attached YouTube video showing Baldwin waiving her arms while dancing on a stage with the popular Wisconsin rock band V05. Some of the band members were dressed in Wonder Woman costumes as the band played the theme song for the Wonder Woman TV series.

Nemoir stated in his email that Baldwin was scheduled to discuss “heartland values” in her Democratic Convention speech.

“Clearly, there’s no one better positioned to talk ‘heartland values’ than Tammy,” he said in the email.

Baldwin supporters called the email a form of gay baiting, saying it was an attempt to question Baldwin’s values because she appeared at an LGBT Pride event. A Thompson campaign spokesperson said Nemoir was acting as an individual and not on behalf of the campaign when he sent the email and video.

While the Thompson campaign’s negative TV ads steered clear of Baldwin’s sexual orientation, they sought to portray her as an ultra liberal politician out of touch with the needs of the state and the country.

One ad pointed to Baldwin’s longstanding support for a single payer health insurance system, quoting her as saying several years ago that the single payer system she supported is a “government takeover of medicine.” Another ad noted that Baldwin voted four times against economic sanctions for Iran, criticizing her judgment on a key foreign policy issue.

U.S. Senate Candidate Rep. Tammy Baldwin (D-Wisc.) speaking at the Democratic National Convention in Charlotte, N.C. (Blade file photo by Michael Key)

Baldwin responded to the health insurance attack by saying she voted for and continues to support the Affordable Care Act, President Obama’s health insurance reform measure that Congress passed two years ago. She said her support for a single payer system was “moot” since the Obama measure is about to be implemented.

She said she voted against sanctions for Iran at a time when she was hopeful that dissident groups in Iran would overturn Iran’s government and establish a true democratic system. She said she began voting for sanctions after determining that the opposition forces didn’t have the strength to change the government.

A Thompson campaign attack ad that drew expressions of outrage from Baldwin’s campaign and its supporters showed video footage of the devastation of the World Trade Center in New York following the Sept. 11, 2001 terrorist attacks and denounced Baldwin for voting against a 2006 House resolution honoring victims of the attacks.

Baldwin said she voted for at least four other 9/11 resolutions honoring victims of the terrorist attacks but voted against the 2006 resolution because it included other provisions on unrelated issues with which she disagreed.

In her own TV ads, Baldwin fired back at Thompson, citing reports by New York firefighters saying the U.S. Department of Health and Human Services, which Thompson headed at the time of the 9/11 attacks, was slow in responding to firefighters’ calls for assistance for their illnesses believed to be caused by the fumes and contaminated dust that engulfed them while responding to the World Trade Center disaster.

Another Baldwin ad criticized Thompson for profiting from the 9/11 tragedy when he became president of a private medical related company that obtained an $11 million federal government contract to assist victims of the attack. Thompson joined the company after leaving his post as HHS Secretary.

A separate Baldwin ad attacked Thompson for having personal investments in companies that do business with Iran. Thompson said the investments were in stock, which he said he immediately sold when he learned the companies that issued the stock had investments linked to Iran.

“In one of the most phenomenally negative years ever, the Wisconsin Senate race stands out this fall as perhaps the most negative race in the entire country,” the Journal Sentinel quoted Ken Goldstein, a political scientist and observer of Wisconsin politics, as saying.