Poll Tracker

Bunning has accused McConnell and Texas Sen. John Cornyn, head of the National Republican Senatorial Committee, of trying to undermine him, and threatened to file a lawsuit if they back a GOP primary challenger against him.

While four announced or prospective Democrats all lead Bunning right now in PPP's match-ups, Republican Secretary of State Trey Grayson, who has said he would not run unless Bunning retires, had much more competitive numbers against them than Bunning, trailing two and leading two. Grayson's approval-to-disapproval ratio is 46 percent to 19 percent with 36 percent undecided. Grayson's favorability rating among Republican voters is 54 percent to 9 percent with 37 percent undecided while Republicans approve of Bunning by a bare 42 percent to 36 percent with 22 percent undecided.

Here's how both would do in matchups with four Democrats (the margin of error is 4 points):

• Three-term Rep. Ben Chandler leads Bunning 47 percent to 33 percent with 20 percent undecided and Grayson by 40 percent to 34 percent with 26 percent undecided.

• Attorney General Jack Conway leads Bunning 42 percent to 33 percent with 26 percent undecided and Grayson by 37 percent to 33 percent with 30 percent undecided.

• State Auditor Krit Luallen leads Bunning 42 percent to 34 percent with 25 percent undecided but Grayson leads Luallen by 36 percent to 34 percent with 30 percent undecided.

• Lt. Gov. Daniel Mongiardo leads Bunning 43 percent to 36 percent with 21 percent undecided but Grayson leads Mongiardo 40 percent to 36 percent with 24 percent undecided.