What is striking is that even some young social conservatives who do not want their party to abandon its platform on culture say Republicans would de-emphasize those issues. Anna Page, 19, a Wellesley freshman attending CPAC, said support for same-sex marriage was now a matter of “pure statistics” among millennials.

“If the party wants to move forward and appeal to our generation they have to appeal to the majority to succeed,” Ms. Page said.

Zach Pohl, an Ohio State junior who was strolling through CPAC wearing a Russian-style winter hat with “OBAMA” and the Soviet hammer and sickle emblazoned on it, said he was not really moved by the same-sex marriage issue.

“Religiously, I don’t agree with it, but at the same time I don’t really care,” Mr. Pohl said.