DURHAM, N.H. — Bernie Sanders ignored snowflakes and a flurry of political attacks as he crisscrossed southern New Hampshire Monday, attending large rallies capped by a rock concert that drew a crowd of young people — a voting bloc that helped him nearly tie rival Hillary Clinton in last week’s Iowa caucuses.

As the concert wound down, the musicians reminded students to vote Tuesday, and gave information about polling locations and transportation options.

Students cheered, and promised to check the ballot for Bernie. When Sanders finally arrived, he told the students that large money interests “don’t want you to vote.” Unlike the Super Bowl, Sanders said, “Democracy is not a spectator sport.”

“Democracy, in fact, is an extremely radical idea,” Sanders added. “And what it says is that all people, not just kings and queens and czars and billionaires, but all people, have a right to determine the future of their country.”