This post has been updated.

Donald Trump has been at the top of the national Republican field for nearly 100 days. Not quite, meaning that the Drudge Report jumped the gun a little with this link.

But he's been ahead for months, and after seeing his lead wither away a bit, jumped back up thanks to new polls, including one from The Washington Post and ABC News.

The link on Drudge directly beneath the one above, though?

Sure enough, a new Quinnipiac University poll has Trump in second place in the first-voting state of Iowa -- and not only in second, but down by eight points.

Trump's response? Retweeting someone who implied that Iowan intellects have been contaminated by the corn.

("Donald Trump has decided after losing one IA poll that Iowans are dumb!," a Jeb Bush adviser replied. "Wow. Unreal.")

Update, 3:00 p.m.: Trump deleted his retweet of the original tweet. His explanation?

This is the second time Trump has blamed an embarrassing tweet on an intern doing the tweeting. In July, an intern took the flak for tweeting a picture that included men in Nazi uniforms. Trump has also bragged about the personal touch he uses with his account, such as when he showed off his mentions to a Times reporter.

It's one poll, but it's clear why Trump isn't happy.

Even as his national lead had started to drop, Trump's leads in Iowa and New Hampshire were relatively stable. There's less polling in the states, meaning that the polling averages don't change as often, but he often cites state polls as examples of how dominant his campaign has been.

That big dip in the Iowa numbers at the end there is a problem though. It's partly, again, because there are fewer Iowa polls. (Because it's an average, he's not trailing Carson in Iowa just yet.) But it's a problem because for a long time, Trump was doing better nationally than he was in Iowa. That changed at the end of August, when he was suddenly doing much better in Iowa than he was nationally. But now, he's doing much worse.

Contrast that with Ben Carson, who's Trump's main competition at this point and the beneficiary of Iowa's corn-addled brains.

Carson had been doing better in Iowa than he was nationally, until relatively recently -- thanks to his national improvement. If Carson is still doing well nationally and does even better in Iowa, that's a big problem for Trump's argument that he's the clear front-runner.

Which, of course, sets aside the fact that Trump just called Iowa voters stupid. Republicans have proven very willing to forgive Trump's disparagement of Mexican immigrants, Megyn Kelly and John McCain. Whether or not they'll forgive Trump disparaging Republican voters is a whole different question.

It seemed inevitable that, at some point, Trump would have to deal with not being the front-runner in at least one state. That point may have arrived, thanks to Iowa. So far, Trump's not dealing with it well.