The short answer is that the left has Media Matters who's stated mission is to monitor every word spoken by republicans, especially the president, and to spin it and throw it out to the salivating mongrels in the left wing blogs for publication. The left has no sense of humor so a joke told by the president would be spun as a lie. An exaggeration is in the mind of the beholder and all politicians exaggerate but if it's a republican it will always go down as a lie in the minds of the crazy left. Republicans have no propaganda source like MM and they have better things to do than whine about jokes and exaggerations.
Yea it's a ******* joke when POTUS tells Americans that his campaign was wiretapped, and spied on for political reasons by a prior President.
It's a ******* joke when he writes a letter in his son's name filled with bullshit on why he was holding meetings with Russians.
It's a ******* joke when he fires the FBI director for supposedly going too rough on Hillary, only to later publicly admit it was actually about "the Russia thing"
HAHA! HEHE! Such funny jokes!

Can laugh all day too because it's always showtime at the bullshit factory that is Trump.