This week, those two cultural phenomena — politics and football — are coming together again in an extraordinary, and for the league, uncomfortable way on the country's biggest sports stage.

The Super Bowl, scheduled for Sunday night in Houston, is infused with national politics like never before. Fox's pregame telecast will include an interview of President Trump by Bill O'Reilly. The owner, coach and star player of one team, the highly successful New England Patriots, are friends of the president's.

Last Sunday, hundreds of people opposed to the president's immigration policy protested at the convention center where the N.F.L. is holding many of its events for fans. The next day, many players on the Falcons and Patriots — including Mohamed Sanu, who is Muslim — were peppered with questions about their thoughts on the president and his temporary ban on refugees from some Muslim-majority countries.