Sen. Sherrod Brown (D-Ohio) has maintained a 15-point lead over his Republican rival, Ohio state Treasurer Josh Mandel, according to a new poll.

Brown led Mandel 49-34 when Quinnipiac University polled the race in October. Both have dropped two points in the past three months, and Brown now takes 47 percent to Mandel’s 32 percent.

Forty-two percent of Ohio voters say they view Brown favorably, with 30 percent saying they don’t have an opinion. But 69 percent say the same about Mandel, highlighting the challenge for the young, first-term treasurer to raise his name recognition in the Buckeye State.

“Mandel is pretty much an unknown to most Ohio voters and the race will be determined by whether Mandel’s ability to fill in the blank in voters’ minds positively exceeds Brown’s ability to do so about him negatively,” wrote Quinnipiac’s Peter Brown, who is not related to the senator, in a polling memo.

- This post was updated at 2:39 p.m.