Kentucky Secretary of State Alison Lundergan Grimes will seek the Senate seat now held by Republican Leader Mitch McConnell.
"Kentucky is tired of 28 years of obstruction," Grimes told an afternoon news conference, according to the Lexington Herald-Leader.
McConnell, first elected to the Senate in 1984, has been under fire from both liberals and conservatives. Democrats have painted him as having hung around Washington too long; conservatives say he's been too timid in pushing their agenda.
Grimes, though, faces an uphill fight. The Herald-Leader reports that McConnell has raised $13 million for his Senate bid. And McConnell will undoubtedly try to tie her to the Obama administration. Republican nominee Mitt Romney won 60 percent of Kentucky's presidential vote last year, while Obama took about 38 percent.
The Herald-Leader reported several other possible Democratic candidates are considering seeking the nomination, including former Miss America Heather French Henry and former state party chairman Bill Garmer. Actress Ashley Judd considered the race but elected not to enter.