Wisconsin Democratic Representative Tammy Baldwin made history today by becoming the first openly gay US Senator, defeating former governor Tommy Thompson in the most expensive Senate race in state history.
The Senate race was the most expensive in state history with the two candidates raising at least US$65 million.
The outcome is another blow to Republicans, who needed to make a net gain of four seats to take a majority in the US Senate.
Baldwin assumes the seat of retiring Democrat Herb Kohl, who is finishing his fourth term in the Senate.
The 50-year-old Baldwin, first elected to Congress in 1998, also becomes the first woman senator from Wisconsin with her victory Tuesday.
Although historically significant, Baldwin's sexual orientation never became a major topic on the campaign trail.
Baldwin, who represents Dane County, a Democratic stronghold of the state, is expected to be replaced in the House by Democrat Mark Pocan, another openly gay politician.
Baldwin, one of the leading liberals in Congress, moved to the center during the campaign, promising to support investments in infrastructure, education and research to create jobs.
She also painted Thompson as favoring tax cuts for the wealthy.
Throughout the bruising campaign, Thompson argued that lower taxes, fewer regulations, large spending cuts and entitlement reform will boost the sluggish US economy.
He also attacked Baldwin for supporting President Barack Obama's health care reforms.
Thompson moved more to the middle as the campaign went on, describing himself during the race against Baldwin as a "moderate conservative".