What did Donald Trump do today?

He lied about holiday sales on Christmas.

At 2:32 on Christmas Day, Trump went to Twitter to post what might have looked like some mildly good economic news.

It's not true.

As conservative writer and former George W. Bush speechwriter David Frum noted, there are two different lies in that one sentence. First of all, it simply isn't the biggest increase in holiday sales, not even in recent years. In 2010, for example, they were up 5.5% from 2009.

The second lie is the lie of omission. Holiday sales were roughly average this year—a big increase over last year, because of the terrible numbers in 2018, when Trump was also president.

Trump often brags that economic indicators are the highest they've "ever been"—stock market figures, number of Americans employed, and so forth. Of course, numbers like that are supposed to get a little bigger than they've ever been before, each year, because of normal inflation and population growth. Bragging about it is a little like bragging about your parenting skills because your 3-year-old has grown taller over the last year. It's not clear whether Trump genuinely doesn't understand this, or simply thinks voters won't.

The flip side of this is that Trump also frequently denies bad news exists, or ignores it completely. Again, it's hard to say whether he genuinely can't understand that he might have failed in some way, or just knows better than to be straight with voters about it. 

So what?

• People who have actually succeeded don't need to lie about what they've done.