Koster was originally elected as attorney general in 2008 as a Democrat after switching from the Republican Party.

Koster won despite accusations that his campaign violated state law in raising money from multiple committees.

He also survived the disclosure that he played a supporting role in a plagiarism episode that damaged Attorney General William L. Webster’s campaign for governor in 1992.

Fresh out of law school, Koster worked for Webster, a Republican, as an assistant state attorney general.

100% reporting (3,420 of 3,420 precincts)[8] Martin, who served as chief of staff for Governor Matt Blunt from 2006 until November 2007, won the Republican primary in a landslide, 72%-28% and become the party's nominee.