Kentucky Secretary of State Alison Lundergan Grimes, one of the few potential big-name Senate recruits left for Kentucky Democrats in 2014, will make an announcement about the race Monday.
AP reports that Grimes will huddle with advisers at 2:30 p.m. Eastern time and brief reporters at 3 p.m.
A series of Democrats have passed on the race, most notably actress Ashley Judd, leaving Grimes next in line in one of Democrats' top-targeted states.
Democratic groups have begun advertising against Senate Minority Leader Mitch McConnell (R-Ky.), even in the absence of a Democratic challenger.
Update 11:59 a.m.: Jonathan Hurst, Grimes's campaign manager for her secretary of state campaign, says he doesn't even know what she'll announce.
"I don't know what she's leaning towards. She hasn't told me," Hurst told WFPL. "I couldn't make a guess on it and be honest about it."