Fighting from behind in the polls, Brown was combative throughout the hour-long debate against Democratic Sen. Jacky Rosen.

Rosen told reporters after the debate that she prioritized discussing issues over exchanging personal attacks. She’s leading the polling by nearly 8 points

Mr. Brown, who has never held elected office, has found himself outpaced by Senator Jacky Rosen, the low-key and well-financed Democratic incumbent. A debate Thursday night presents a key test.