For months, Donald Trump's argument to Republican presidential primary voters has been simple: I'm winning.

As in, polls in places such as Iowa and New Hampshire show me winning, therefore I am winning, therefore my "message" is working. You could not like Trump or think he was a serial exaggerator, but you couldn't take that one fundamental fact away from him: He was winning in every state and national poll.

What would happen if Trump began to slip in a state or two? Given the size of the GOP field and the time before anyone actually votes, that seemed like a probable scenario — but one that Trump had never had to deal with as a candidate. Would he show resilience, revamping some of his message and making the classic political argument that polls go up and down and — this is my favorite — that the only poll that matters was the one on Election Day? Or would he double down on his bravado and argue that all the surveys, which he had touted for so long, were now in fact wrong?

We have an answer! A series of Iowa polls came out in the past 72 hours showing Trump trailing Ben Carson by wide margins; Trump reacted by insisting they didn't reflect reality. "I love Iowa, and I honestly think those polls are wrong," he said in Miami on Friday. "Both of those polling companies do not like me."

Trump expanded on that sentiment during a New Hampshire town hall gathering hosted by NBC's Matt Lauer on Monday morning:

The Des Moines Register is a terrible paper as far as I’m concerned. It really is. Very liberal paper, by the way. I believe — and I’ve been winning in Iowa. And by the way, I have other polls in Iowa that say I am winning. This is two small polls. And all over the country, I am winning by massive numbers. But I will say I think I’m winning in Iowa. I think I’m doing really well with evangelicals, with tea party, with everything else. We’ll see what happens — but that was the only one where I had a slight lead.

Not really. Check out this chart from Fix posse member Philip Bump that shows Trump's slide in Iowa:

The data is clear.  Trump's appeal in Iowa has worn off. That shouldn't be surprising because Iowa always seemed like an odd fit for Trump. It's a state that has promoted social conservatives (such as Carson) in each of the past two Republican presidential caucuses. Trump is many things to many people but a social conservative he is not. Trump's tell-it-like-it-is appeal always seemed — at least to me — to be a better fit for New Hampshire, a state that has shown a willingness to vote for outsiders who speak truth to power.

But, why Trump is behind in Iowa isn't the point here. It's that he is behind in Iowa and refuses to acknowledge it — choosing instead to slam the Des Moines Register poll as somehow liberal. Now, plenty of surveys — and the pollsters who conduct them — aren't that great.  The DMR poll, which is conducted by Ann Selzer, is not one of them. Selzer's track record is as close to perfect as you can find in the polling business — even when her numbers have flown in the face of other published surveys. No matter what Trump thinks of the Register (or Selzer), there's no denying that the woman knows how to poll Iowa better than anyone else.

What Trump is doing is creating an alternate reality where he's still winning everywhere and anyone who says differently is either a) out to get him b) a loser or c) both. That line of thinking will appeal to his most hardcore fans, who think that the system is rigged and that the only truth is the truth that Trump tells them. Like this person:

But that's not a big enough group to elect Trump to anything — or even, probably, for him to win even a single primary or caucus. To do that, Trump needs people who are not devotees but who are attracted to the combination of his un-politician profile and the fact that he does always appear to win in life. If it's clear to most reasonable people that Trump isn't winning but he continues to insist he is, he probably will lose a lot of those folks.

Winning is a great message until you stop winning. That's a new reality Trump needs to face.