“It is really great to be home,” she said. “A lot of people are trying to distract us now, but, I want you all to know that we are not going to let them.”

Mr. Trump, however, continued to focus on the issue, and the language. One day after disavowing the “send her back” chant that broke out at his rally on Wednesday in North Carolina, the president was back on Twitter Friday to suggest that the widespread outrage over the phrase — which caused alarm among congressional Republicans and members of his inner circle who prodded him to reject it — had been misplaced.

He groused about the coverage of Ms. Omar’s warm reception upon her return from Washington. “They even covered a tiny staged crowd as they greeted Foul Mouthed Omar in Minnesota,” Mr. Trump wrote, adding that people in the state “can’t stand her and her hatred of our Country.”