Trump still leads by a broad 10 points nationally in the latest ABC/Washington Post poll, as well as in almost every other state-level poll, including New Hampshire, South Carolina and Nevada. But as one of his strongholds begins to fall, Trump is now blasting pollsters in Iowa and insisting that he still holds first place.
But Carson has been surging in Iowa, even though he has been taking a break from public campaign events over the past few weeks, making only a limited number of visits to Iowa.
So what's causing Iowa voters to trade one outsider for another? Here are five things we've learned from these brand new polls.
1. Iowa evangelical Christians have jumped on the Carson bandwagon (and off Trump's)
Carson has bolted out in front among evangelical Christians, exactly doubling Trump's support in the new Monmouth poll. Carson earns the support of 36 percent of Iowa evangelicals, while Trump garners only 18 percent.
Recent Quinnipiac and Bloomberg/Des Moines Register polls show similar numbers, with Carson leading Trump among evangelicals by at least 15 points.
Compare this to August, when Carson had just a slim lead over Trump among evangelicals: 29 percent to 23 percent in a Monmouth poll.
And these Iowa Republicans think Carson's faith is important. When asked whether they liked that Carson says he was guided by his faith in God, a whopping nine in 10 Iowa Republicans said they found it attractive, and more than six in 10 said it was "very attractive."
But while evangelicals rally around Carson, some Republicans seem wary of Trump's faith. Only about a third of Iowa Republicans consider the real estate mogul a committed Christian, while 28 percent say he isn't and 40 percent say they're not sure.
2. Carson's not only for the die-hard conservatives.
A recent Monmouth poll in Iowa shows Carson leading Trump among "somewhat conservative" Republicans by more than 20 points, 39 vs. 18 percent. Just two months ago, Carson and Trump were running even.
And a recent Quinnipiac poll also shows Carson making huge strides among more moderate Republicans, while continuing to dominate the race among very conservative voters by a two-to-one margin, 32 percent vs. 16 percent according to Quinnipiac.
3. Iowa Republicans just think he's a good guy -– by huge margins.
Carson's favorability ratings among Iowa Republicans are astronomical, hitting 84 percent in all three recent polls showing Carson ahead –- Bloomberg/Des Moines Register, Monmouth University and Quinnipiac. And the number of Iowa Republicans with a negative view of Carson is hovering at just one in 10.
And by a landslide, Iowa Republicans also think Carson is more honest and trustworthy than Trump, according to a recent Quinnipiac poll. Nine in 10 Iowa Republicans say Carson is honest and trustworthy, compared to less than half who say the same about Trump, even though the former reality TV star often insists that he too is a good guy.
Not to mention, when people were asked whether Carson cares about their needs and problems, 87 percent said yes -– almost 40 points more than said the same of Trump.
4. Carson is winning over more men -– and running up the score among women in Iowa.
With Trump's controversial comments about women plaguing his campaign, Trump has generally done better among men than among women.
But in a remarkable 180-degree shift over the last two months, Carson has gone from trailing Trump by a 27-17 percent margin among men in August to leading Trump by 11 points now, a margin of 31-20 percent.
And Carson is running up the score among women. A recent Iowa Quinnipiac poll shows him more than doubling Trump's support among women. Carson garners a third of Iowa GOP women, while Trump draws only 13 percent -– running roughly even with Marco Rubio at 15 percent. In August, Carson and Trump were running almost even among men and women.
5. Iowa Republicans agree with what Carson has to say.
Not only do Iowa Republicans like Carson (a lot), they also say they agree with most of what he has to say.
Iowa Republicans were asked whether candidates shared their values -– and, you guessed it – Carson topped the list with 84 percent saying that they shared the same values as the new Iowa frontrunner. Trump, meanwhile, was much worse off as only 42 percent of Iowa Republicans said Trump shared their values.
It's not that Trump's favorability has gone down: He was at 61 percent in August and still sits at a virtually identical 59 percent, according to a recent Bloomberg/Des Moines Register poll.
But instead, they like what Carson has to say. The same Bloomberg poll found that three-quarters say they are attracted to his inspiring personal story.
His statements that have raised controversy in some areas aren't affecting him there either: His comparison between Obamacare and slavery is attractive to 81 percent of Iowa Republicans and his comments about gun control and the Holocaust were attractive to 77 percent, according to the Bloomberg/Des Moines Register poll.