In this morning's Washington Post, an explanation of a video in which Joe Biden was edited to make it seem he was supporting Trump's reelection:

Twitter applied its new “manipulated media” label for the first time on Sunday to a deceptively edited video of former vice president Joe Biden. The video was shared by White House social media director Dan Scavino and retweeted by President Trump.

The video was the first test of a new policy the social media company implemented March 5 to label tweets that contain manipulated or synthetic media, ranging from edited videos to more sophisticated examples known as “deepfakes” that can fabricate events that never happened.

In this case, the altered video of Biden — who has surged to the front of the Democratic race to face Trump in November — is based on a speech he gave in Kansas City, Mo., on Saturday. It was then shared on Twitter by Scavino, only edited to make it appear as if Biden inadvertently endorsed Trump for reelection.

The version of the video shared by Scavino showed Biden stumbling on a line during a speech, then saying: “Excuse me. We can only reelect Donald Trump.”

But the edited video deleted the second part of the former vice president’s sentence. The whole thing said: “Excuse me. We can only reelect Donald Trump if in fact we get engaged in this circular firing squad here. It’s got to be a positive campaign.”