Senate Minority Leader Mitch McConnell (R-Ky.) is nearly deadlocked with Democratic challenger Alison Lundergan Grimes, according to a new Bluegrass Poll sponsored by several Kentucky media outlets.

The poll gives McConnell 47 percent to Grimes' 45 percent among likely voters -- a difference that falls within the survey's margin of error. One quarter of voters said they might change their minds before Election Day.

Past Bluegrass Polls gave Grimes a 4-point edge in February and a 1-point edge in May. In the intervening months, McConnell's favorable rating has risen, from a dismal net negative-23 in February to a net negative-7 in the latest survey. Most of the improvement comes among Republicans, who have largely rallied around his candidacy since he fended off tea party challenger Matt Bevin in a contentious primary. McConnell's rating among GOP voters is now 65 percent, up 19 points since February.

Grimes' net favorable rating stands at plus-3. While the Kentucky secretary of state has gained in name recognition since the beginning of the year, 31 percent of voters still said they had no opinion or a neutral opinion of her. Her lead among female voters has also narrowed significantly, from 12 points in February to just 1 point in the newest survey.

Polling on the Kentucky Senate race has been volatile and dominated by partisan sponsors on both sides. The other most recent nonpartisan survey, an online YouGov poll for CBS and The New York Times released Sunday, gave McConnell a 4-point edge. HuffPost Pollster's average, including all publicly available surveys, gives McConnell just under 47 percent to Grimes' 44 percent.