Those 45 and older favored Blackburn by 9 percentage points, while women younger than that backed Democratic former Gov. Phil Bredesen over Blackburn by 10 points.
The data was gathered by AP VoteCast, a nationwide survey of 115,000 voters and 22,000 nonvoters.
Age in general represented a breaking point, with voters 45 and older favoring Blackburn by 18 percentage points, and those younger preferring Bredesen, 51 percent to 46 percent. Men, meanwhile, preferred Blackburn over Bredesen by 20 points.
With her election Tuesday, Blackburn will replace Sen. Bob Corker, who's retiring.
For AP's complete coverage of the U.S. midterm elections: http://apne.ws/APPolitics
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