“Turn off the NFL,” reads a digital ad produced by the nonprofit America First Policies, which planned to begin spreading the message on social media Sunday afternoon. A political group with close ties to President Donald Trump is amplifying his attack on professional athletes who kneel during the national anthem as a form of protest. “Turn off the NFL,” reads a digital ad produced by the nonprofit America First Policies, which planned to begin spreading the message on social media Sunday afternoon. The ad includes a photo with Trump, hand over his heart, and a #TakeAStandNotAKnee hashtag. It follows Trump’s...