Donald Trump is a serial liar. Okay, to be a bit less Trumpian about it, he has trouble with the truth. If you look at Politifact, the Pulitzer Prize-winning site that examines candidates’ pronouncements for accuracy, 76 percent of Trump’s statements are rated either “mostly false,” “false,” or “pants on fire,” which is to say off-the-charts false. By comparison, Hillary Clinton’s total is 29 percent.

But if Trump doesn’t cotton much to the truth, he doesn’t seem to cotton much to his own ideas, either. He waffles, flip-flops and obfuscates, sometimes changing positions from one press appearance to the next, as Peter Alexander reported on NBC Nightly News this past Monday — a rare television news critique of Trump.

I say “rare” because most of the time, as Glenn Kessler noted in The Washington Post this week, MSM — the mainstream media — just sit back and let Trump unleash his whoppers without any pushback, even as they criticize his manners and attitude.

In an ordinary political season, perhaps Trump would be under fire for his habitual untruths, like the one that Ted Cruz’s father might have been involved with Lee Harvey Oswald. This time around, though, neither the media nor the public — least of all his supporters — seem to care. Which leads to the inescapable conclusion that these days, as far as our political discourse goes, truth, logic, reason and consistency don’t seem to count for very much.