In the Ohio race, incumbent Sherrod Brown defeated Republican State Treasurer Josh Mandel.
Former Dayton Daily News editor Ellen Belcher says when Mandel decided to run against Brown, not many people gave him a chance - but when money started pouring in, the tide started turning.
"Its been up and down and there were moments when people thought Sherrod Brown could actually lose this. I think this is one of those times where those who think that money can't buy an election are proven right," says Belcher.
Despite being outspent in the campaign, Democrat Sherrod Brown was re-elected to the Ohio State Senate. Brown won 50 percent of the vote to Mandel's 45 percent.