Conducted May 12-13, , Lt. Governor Daniel Mongiardo wins 46% of the vote to Attorney General Jack Conway's 26% among Democrats who voted in either the 2008 or 2007 Democratic primaries. Among registered Democrats, Mongiardo wins by 15 points. Mongiardo gets 43% of the vote, Conway has 28%, with 29% undecided. The poll conducted by Garin Hart Yang Research among 336 registered Democrats has a margin of error of plus or minus 5.4%.
(Caveat: these summary data might gloss over such variable as likely and committed voters.)