Nine years ago, Chris Koster was a state senator, a former Cass County prosecutor and a rising star within the Missouri Republican Party. Many speculated he would eventually run for governor.
And now he is running for governor, but as a Democrat.
Koster switched parties in 2007, a stunning move that has set the course for his unusual political career. He remains the highest-profile politician in Missouri, at least in modern times, to have made such a move