In the last few years, only one Senator has switched parties.
Republicans had been lobbying him to switch parties since 1998.
Here's a guy who had the courage to switch parties.
Democrats then spoke about trying to get a couple of Republicans to switch parties, which would have given them control.
In 1996, he switched parties to become a Republican after years of heat from his party.
The district was ranked as one of the top ten most likely to switch parties in 2008.
His decision to switch parties in 1950 was met with little controversy.
He was first elected as a Democrat, but switched parties in 1995.
He was asked several times to switch parties and become a Republican.
The seat has switched parties in each of the last four elections.