No American president has ever lied as much as Donald Trump does. In his first 928 days in office, he has told 12,019 lies -- an average of about 13 lies every day. That would be bad enough, but he seems to be getting worse. Since he crossed the 10,000 lie mark last April, he has been averaging about 20 lies per day.
It's easy to see why poll after poll has shown that a significant majority of Americans consider Trump to be dishonest and untrustworthy. Trump has no regard for the truth. He says what he wants to say (what he thinks will make him look good and his supporters will like) whether false or not. He just doesn't care.
Expect his lying to get even worse once the 2020 campaign starts in earnest.