A statement that is correct on its face can be irrelevant and – if wrongly presumed to be relevant – misleading. It won’t become “mostly wrong” in itself, no matter how misused.
President Trump tweeted on Feb. 25:
The media has not reported that the National Debt in my first month went down by $12 billion vs a $200 billion increase in Obama first mo.
If the national debt did what Trump said it had done, and if the media had not reported it by the time of Trump’s tweet, the statement above must be correct. (It can be logically correct even if the subordinate clause is not, as in “the media is not reporting the Earth is flat.”) Politifact agrees with the former, does not discuss the latter, but calls the tweet “mostly wrong” nonetheless. Why?
Certainly the most natural interpretation of the tweet is (a) the decrease in the national debt means something, probably something good; and (b) Trump deserves some credit for it. There’s no arguing with Politifact that (a) is wrong. To begin with, I would be looking at net debt, that is, total debt less the cash balance. Taking Politifact’s numbers for granted, it follows that the net national debt actually went up by $117 bln from the inauguration day to Feb. 22. As for (b), well, whatever.
Which still does not make the original tweet “mostly wrong,” merely pointless.