Senate Minority Leader Mitch McConnell (R-Ky.) speaks at the Fancy Farm picnic August 2, 2014 in Fancy Farm, Kentucky. (Photo by Win McNamee/Getty Images)

Senate Minority Leader Mitch McConnell (R-Ky.) holds a slight lead over Democratic challenger Alison Lundergan Grimes, according to a new poll released Wednesday.

The CNN/ORC International poll of those likeliest to vote, which was conducted Thursday through Monday of the holiday weekend, shows McConnell leading Grimes 50 percent to 46 percent, an advantage equal to the poll's margin of error.

The survey is the latest sign the Kentucky race is shaping up as one of the most competitive in the country. Grimes and McConnell are competing in a closely-watched race in the battle for the Senate majority. Both candidates have been raising huge sums of money ahead of what's been shaping up as a nasty campaign.

Kentucky appears to be Democrats' best pickup opportunity in the battle for the majority. Republicans need to gain six seats to take control of the chamber and have many more pickup opportunities than Democrats.

The poll shows that McConnell has more crossover appeal than Grimes. He's pulling the support of 16 percent of Democrats -- more than double the share of Republicans Grimes is picking off.

President Obama's approval rating is just 29 percent among adults in the state -- and so Republicans have routinely tried to link him to Grimes. For her part, Grimes has sought to keep Obama at arm's length, campaigning instead with former president Bill Clinton.

Most voters have decided which candidate to support, while 19 percent say they might change their mind between now and Election Day.