The White House has belatedly backed down from a racist video shared on President Donald Trump’s social media feed after blowback from Republicans. The video promoting false claims of voter fraud concluded with a brief clip of images of former President Barack Obama and former first lady Michelle Obama’s heads affixed to the bodies of apes. After initially trying to defend the post and leaving it up for hours — even labeling the outrage “fake” — the White House eventually gave into bipartisan backlash, removed it and changed its tack. Its new explanation: The video was “erroneously” posted by a...