Democrats could flip the open U.S. Senate seat in Tennessee occupied by retiring Republican Sen. Bob Corker, if numbers captured by a new poll released Thursday hold steady.

Democratic candidate Phil Bredesen has 48 percent support among likely voters, a slim 2 percentage point lead on Republican opponent Marsha Blackburn, according to research conducted by NBC News and the Marist Institute of Public Opinion. Only 5 percent of likely voters surveyed remain undecided.