This, the opening line from an Associated Press fact-checking piece on the great Oval Office Garbage fire, is good. More of this, please:
President Donald Trump is living in an alternate reality when it comes to [...]
There you go. It's not that the man tends to lie: it's that the man tends to lie about everything, in every speech. He is incapable of either comprehending or conveying basic facts, and is unable to process explanations given to him about why his favorite claims are wrong.
As far as the meat of the fact-checking goes, it continues to go how it always does. The AP is obliged to point out that Trump is, in his public statements of the last week, largely out of his gourd. He lied again about his own popularity this weekend, or if you don't like to use the word "lied," you can go with "the sitting president is so innumerate that he continues to be unable to decipher even the simplest polls without flagrant errors, always erring to his own advantage."
Other recent lies include a declaration that the United States is the "cleanest country in the planet," which is both wrong and weird; his continued claim that his deficit-exploding tax cut for the wealthy is the "biggest tax cut in history" even though it is not even in the top 10; his assertion that Immigrations and Customs Enforcement is "liberating towns" from "MS-13" in what can only be described as Donald Trump inventing action movies in his own head; and so on. Many of his lies, like the notion that immigration officials are "liberating" captured American towns but the rest of you poor saps don't know about it, are plainly nonsensical.
It was another week of lying about everything, all the time, in stupid ways that only stupid people would believe, for the benefit of himself and those very, very stupid people, and which is so rote at this point that it is almost certain we are going to sooner or later find out that the sitting president is a victim of dementia. That is the charitable explanation, and it is the only possible one. As for why his Republican staff and Republican Party continues to support his delusions and flagrant ethical violations and lawbreaking, there is no charitable explanation. They have abandoned their nation to throw their lot in with an ignorant raving autocrat, and they have done so because they believe supporting the ignorant raving autocrat will gain them, themselves, a spot of power.
Where were we? Ah, yes. He spent the week lying again. Fact checkers note that the frequency of his lies continue to ratchet up; this appears to be in direct correlation to how far the Mueller probe, questioning whether Donald Trump or members of his staff aided and abetted a foreign government's attack on our nation for their own gain, has advanced. In the meantime, Vice President Mike Pence continues to measure the drapes while doing not a damn thing to protect his country, because that is who Mike Pence—and every other party hanger-on—has become.