In the last few weeks, he spent heavily on advertising and was able to narrow the polls. But he never took the lead

Virginia: Former Gov. Tim Kaine (D) vs. former Gov./Sen. George Allen (R)

Final result: Gov. Tim Kaine wins

Allen conceded in a Tuesday night speech and pledged his support to Kaine.

"I congratulated him and pledged my support and cooperation as he undertakes the solemn vows of representing the people of Virginia during very difficult times in our nation's history," Allen said. "We haven't succeeded my friends in winning this election."

The race pitted two former Virginia governors against one another and each pulled from their experience in the state house throughout the race.

Though, Kaine linked himself to Obama and the president's campaigning in Virginia, he also painted himself as someone who had worked with both Democrats and Republicans. Allen, however, tried to turn that link against Kaine -- tying him to Obama and the Democratic Party, where the former Democratic governor served as chairman.

Making that case was costly. When outside and candidate spending was added together, the Kaine-Allen race was the most expensive race in the country. Outside groups, on their own totaled over $50 million, according to the Center for Responsive Politics.

Wisconsin: Rep. Tammy Baldwin (D) vs. former Gov. Tommy Thompson (R)

Final result: Rep. Tammy Baldwin wins

Baldwin, along with outside groups, spent a lot of advertising dollars painting Thompson as someone who left politics to cash in on lobbying. Both Democrats and Republicans officials acknowledge that the attacks drove Thompson's negatives up -- and led to a testy campaign tone.

The Wisconsin Senate seat opened up when Sen. Herb Kohl retired after four terms in the Senate. Thompson, who won a four-way primary for the Republican nomination, was Baldwin's first competition in the race -- she ran unopposed for the Democratic nomination.

The election win makes Baldwin the first openly gay member of the Senate.