MATT STONE/POOL

With David Gregory of NBC News at moderator, Senator Scott Brown and Elizabeth Warren debated at UMass Lowell.

matt stone/pool

The hourlong debate, the second of four, skipped quickly from issue to issue. Above, Brown makes a point.

christopher evans/pool

At times, policy took a back seat to sniping over some political flash points. Above, Warren answered a question.

jim davis/globe staff

Both candidates were aggressive, while often complaining that they were being misrepresented by their opponent.

jim davis/globe staff

Audience members arrived at UMass Lowell’s Tsongas Center before the event.

jim davis/globe staff

Supporters for each candidate were outside.

jim davis/globe staff

Attendees of all ages were showing their colors.