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Donald Trump
Despite the NFL's attempt to appease President Donald Trump, their worst nightmare became a reality when he made it clear that he was not going to take his foot off their neck.
When Trump canceled the Philadelphia Eagles' White House Super Bowl celebration and called out the league for its new national anthem policy, it was just the latest salvo in a 35-year war with the NFL, his oldest rival.
Trump has battled the NFL over the USFL, players, a coach, ownership of a team, safety issues, Deflategate, and social injustice protests. The difference now is that for the first time Trump is winning, and the NFL is in trouble.
Here's a look inside Trump's first war, The Pigskin War: