Two statewide office-holders are the leading candidates in Tuesday's Democratic Senate primary in Kentucky:
Attorney General Jack Conway, 40. Before becoming attorney general, in 2008, he divided his career between private practice and other state government work. Conway unsuccessfully sought a U.S. House seat in 2002.
Lieutenant Governor Daniel Mongiardo, 49. He served in the state Senate from 2001 to 2007. In 2004, he lost to Republican Senator Jim Bunning, in the previous general election for the U.S. Senate seat for which he is running this year. Mongiardo became lieutenant governor in 2007. He is a physician.
Real Clear Politics reports several polls, which average out to a five-percentage-point lead for Mongiardo.
I described the Republican primary here.