On Monday, his deputy campaign manager, Dimitri Kesari, reiterated that Mr. Paul “did not write, edit or authorize” the language.

“He totally disavows what was said and disagrees with it totally,” Mr. Kesari said. “The only responsibility he takes is for not paying closer attention.”…

The question now is whether the newsletters’ reappearance will hurt Mr. Paul with some of his younger supporters. Jake Mescher, a freshman organizer for Mr. Paul at Drake University in Des Moines, predicted that the newsletters would not reduce the ardor of his supporters. “I’ve heard of that four or five times, but it really has not made me wary,” Mr. Mescher said. “He has nothing in his record to suggest that that is part of his personal beliefs as a member of Congress or a presidential candidate.”