Progress Kentucky's other candidates include, among others, Reps. John YarmuthJohn Allen YarmuthBudget hawk warns 'Tax Cuts 2.0.' would balloon debt On The Money: Trump threatens 7B more in Chinese tariffs | Obama mocks GOP for taking credit for economy | US adds 201K jobs in strong August | Dems vow to get Trump's tax returns if they take the House Dems vow to grab Trump tax returns upon taking majority MORE (D-Ky.) and Thomas Massie (R-Ky.), the latter of whom is backed by the Tea Party; Kentucky Secretary of State Alison Lundergan-Grimes (D); and former gubernatorial candidate Phil Moffett, also a Tea Party candidate.

In a statement accompanying the petitions, Shawn Reilly, executive director of Progress Kentucky, echoes what a number of Democrats in the state believe: "It’s unacceptable that someone as unpopular as McConnell would be unopposed for a sixth term."

McConnell was revealed to be the nation's least popular senator in a poll released last month by Democratic firm Public Policy Polling, and though he led a number of Democratic challengers, Judd took 43 percent support to his 47, indicating he might be vulnerable.

Polls released prior to that one, however, indicated the senator is much safer, and he has won four of his five elections with more than 50 percent of the vote and has nearly $7 million in his war chest, a considerable sum for any challenger to surmount.