Democrat Alison Lundergan Grimes hopes to topple Mitch McConnell. (Associated Press)

With Congress gearing up for the August recess, Mitch McConnell can focus on his reelection campaign in Bluegrass State. It looks like the Senate minority leader will have his work cut out for him.

McConnell faces fights on two fronts in his quest for reelection. First, businessman Matt Bevin announced a primary challenge from the right last week. Bevin's an underdog, but he's got the backing of influential conservatives including Erick Erickson, and as we learned in 2010, longstanding GOP senators can't take reelection for granted these days. Rand Paul also upset establishment pick Trey Grayson in the 2010 primary for the other U.S. Senate seat in Kentucky.

Assuming McConnell knocks off Bevin, however, he'll face a second challenge from Democrat Alison Lundergan Grimes, the Kentucky secretary of state. A poll by the Democratic firm Public Policy Polling, conducted for the liberal Progressive Change Campaign Committee and Democracy for America and out this morning, suggests Grimes will give McConnell a run for his money. Not only is the senator's approval underwater, he also trails Grimes head-to-head:

Do you approve or disapprove of the way Republican Mitch McConnell is handling his job as U.S. Senator?



Approve .............................. ............................ 40%

Disapprove.................... .............................. .... 51%

No opinion....................... .............................. .. 9%

(Asked of 1,210 Kentucky voters MOE 2.8%)



If the general election for U.S. Senate were held today, and the choices were Republican Mitch McConnell and Democrat Alison Lundergan Grimes, for whom would you vote? Mitch McConnell .............................. ............... 44%

Alison Lundergan Grimes .............................. . 45%

Undecided..................... .............................. .... 11%

(Asked of 1,210 Kentucky voters MOE 2.8%)

That follows on previous polls that showed a tight race, though previous ones have never shown her leading. In April, PPP found McConnell leading Grimes 45-41, while a late May poll by the same firm found them tied up at 45. PPP had a stellar record in 2012, despite their partisan affiliation. On the other hand, it's well within the margin of error, and a Republican firm found McConnell up eight points, 48-40, just last week. But this is the first poll since Grimes' official campaign launch. Her soft launch was widely derided -- when she announced she would run, Grimes didn't even have a website -- but she held a formal event to jump into the race Wednesday. Back on July 1, Nate Silver examined the race and found McConnell a favorite but not a slam dunk for reelection. But Grimes has the potential to be a formidable candidate, as Dave Catanese pointed out here earlier this month. Though she's only run for office once, she upset a Democratic incumbent and sailed to victory, and her father is a powerhouse in state circles -- and a friend of Bill Clinton's. Poll numbers like this only reinforce how serious McConnell's challenge is.