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In a Republican field so crowded that 10 or more candidates could be on the ballot for the Iowa caucuses, Senator Rand Paul of Kentucky is counting on the calendar to provide him an edge.

The caucuses, set to be held on Feb. 1, 2016, will be the first time since 2004 that colleges will be in session during the voting, so out-of-state students who have registered will be able to participate.

On three recent Iowa trips, Mr. Paul has visited a college town, traditional liberal bastions that most Republicans honor with a wide berth.

On Saturday, he packed a room just off the Grinnell College campus at the town library, where some parking spaces were reserved for “low-emission vehicles.” The crowd, more curious than foot-stomping, was nonetheless more respectful than during a visit to Grinnell by Michele Bachmann, then a Minnesota representative, in 2011, when student protesters forced her to cancel a public speech.

Mr. Paul’s strategists believe his libertarian-themed conservatism, which polls show to be popular with young Republicans, could be decisive in the 2016 caucuses.

“Rand Paul has tremendous appeal among under-30 voters, especially college kids,” Steve Grubbs, his Iowa state director, said. “He speaks about issues that are important to them, and that creates an unusual voting bloc for a Republican.”

His visit to the University of Iowa the day after he announced he was running drew more than 400 people in the state’s most liberal city. In Grinnell, he focused on his opposition to government spying on citizens, the overhaul of drug laws and criticism of Hillary Rodham Clinton for the country’s involvement in places like Libya.

He notably omitted an issue he pushed hard just a few hours later at a forum of evangelical voters: his staunch opposition to abortion.

The students from Grinnell College, a selective liberal-arts school with a comprehensive fee of $58,400, seemed more like curiosity seekers than supporters.

“I want to check him out,” said Ellen Taylor, 19, from Zionsville, Ind., who said she was from a very conservative family but leaned “more closely with a green party.”

T. J. Pearson, 21, from Belleville, Ill., said he would participate in the caucuses next year. “I think Democrats are pretty settled with it, so the more interesting process will be the Republicans,” he said.