Mr. Nelson, whose home state is heavily Republican, said Mr. Schumer had been more than understanding when Mr. Nelson’s votes had placed him at odds with the Democratic caucus.

“He’s not ideological,” Mr. Nelson said. “From time to time, he has said, ‘You have to vote with the people of Nebraska.’ ”

He recalled taking Mr. Schumer pheasant hunting in Nebraska. “He shot three pheasants,” Mr. Nelson said. “He practiced on a course before. And he’s a good shot.”