POTUS has used treason on many occasions. Here is one.
https://twitter.com/realDonaldTrump/status/1097690731882446849?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1097690731882446849&ref_url=https%3A%2F%2Fwww.newsweek.com%2Fdonald-trump-tweets-quote-sean-hannity-says-andrew-mccabe-committed-treason-1335029