Sen. Sherrod Brown’s (D-Ohio) lead over Republican Josh Mandel has expanded slightly, and his margin is back into the double digits, according to a poll released Thursday.
Brown leads Mandel by 14 points in the NBC-Marist poll, besting the first-term state treasurer 51-37. Twelve percent were undecided.
When NBC-Marist polled the race in March, Brown had a 10-point advantage on Mandel. But a Quinnipiac University poll in early May and other surveys from both Democratic and Republican firms had showed Mandel narrowing the gap to just a handful of points.
Both candidates have been flooding the airwaves with television ads — mostly negative — although most of the spending by super-PACs in the race has benefited Mandel.
A Marine veteran and former state lawmaker elected state treasurer in 2010, Mandel is facing scrutiny over contributions he and Rep. Jim Renacci (R-Ohio) accepted from almost two dozen employees of a direct-marketing firm.
Mandel announced Wednesday that he was returning $105,000 in donations out of an abundance of caution while the FBI investigates the contributions, the Cleveland Plain Dealer reported.