MUSCATINE, Iowa — Donald J. Trump spent the last seven months saying he wanted to win. Now he is really acting like it.

On Thursday night, minutes after National Review published a call-to-arms cover story blasting Mr. Trump as a wrecking ball to the conservative movement, his campaign manager leaned on the Republican National Committee, which promptly dropped the magazine as a co-host of a presidential debate in February. Then Mr. Trump turned a sleepy hunting trade show into breaking national news, calling National Review “a dying paper” and excoriating his leading rival, Senator Ted Cruz of Texas, before live television cameras.

On Friday night, the candidate who almost always flies home in his private Boeing 757 to Trump Tower in New York or to his palatial Mar-a-Lago estate in Palm Beach, Fla., instead slept in a Holiday Inn Express in Sioux Center, Iowa. (“Good mattress,” he said afterward. “Clean.”)