A notable number of Republican lawmakers broke sharply with the White House on Friday after President Trump posted — and later deleted — a video on social media that included a clip of former President Obama and former first lady Michelle Obama depicted as apes. Republicans have generally been careful about voicing criticisms of Trump, and Friday’s episode began with a more typical partisan line, with Democrats quick to condemn the video as racist. But then Sen. Tim Scott (S.C.) — a close Trump ally and the only Black Republican in the Senate — soon joined them, paving the way...