The video was apparently recorded during a pro-Trump 2020 golf cart parade at The Villages, a retirement community in Sumter County, Florida.
At one point, the parade was met by a group of supporters of Democratic presidential candidate Joe Biden.
Both sides hurled profanity-laden insults at each other.
The president, in his tweet, thanked the “great people” supporting him.
Senator Tim Scott, the only black Republican in the Senate, said the president should take the tweet down, which he did after four hours.
A White House spokesman said the president didn’t hear the “white power” chant.
The spokesman said the president loves The Villages, and he re-tweeted the video when he saw the enthusiasm of his supporters.
President Trump has long denied being a racist and claims he has done more for black people than any other president, with the exception of Abraham Lincoln.