Get ready for a new context shift in the Republican presidential sweepstakes. There could be no greater contrast in the GOP primary race than the brash bluster of Donald Trump and the calm, philosophical demeanor of Ben Carson. Both approaches seem to be working, though, as Carson has tied Trump in the latest Monmouth University poll in Iowa:

The Monmouth University Poll of likely Iowa Republican caucusgoers finds Ben Carson and Donald Trump tied for the top spot. This marks the first time since July 26 that a poll in any of the first four nominating states has not shown Trump with a nominal lead. Not surprisingly, given the top two contenders in the poll, most Iowa Republicans prefer someone without a traditional political pedigree. At this early stage, though, the vast majority of voters say their eventual support could go to one of several other candidates in spite of their current preference.

When Iowa Republicans are asked who they would support in their local caucus, Ben Carson (23%) and Donald Trump (23%) tie for the top spot. The next tier of candidates includes Carly Fiorina (10%) and Ted Cruz (9%), followed by Scott Walker (7%), Jeb Bush (5%), John Kasich (4%), Marco Rubio (4%), and Rand Paul (3%). The last two Iowa caucus victors, Mike Huckabee and Rick Santorum, each garner 2% of the vote. None of the other six candidates included in the poll register more than 1% support.

“These results mark a significant shake-up in the leaderboard from Monmouth’s Iowa poll taken before the first debate,” said Patrick Murray, director of the independent Monmouth University Polling Institute in West Long Branch, NJ. “Carson and, to a lesser extent, Fiorina have surged, while Walker has faded into the background.”

No kidding. Walker’s fade almost exactly matches the Carson surge, in fact. Walker went from 22% and the lead in July to 7% and fifth place in August. Carson had third place with 8% in July and went to 23% and a tie for the lead a month later. Clearly, Iowans have liked what they have seen and heard from Carson so far.

That may seem odd, given the drastically different styles of the two frontrunners, but they have two key points in common. Neither of them have held public office before, and both are running on an anti-establishment populist platform. In third place, the aggressive but disciplined businesswoman Carly Fiorina comes in at 10%, making it a trifecta.  Seen from that perspective, well over half of Iowa Republicans are rebelling against the party establishment, and splitting their vote on style more than anything else.

Interestingly, only 22% select Carson or Trump as a second choice, though. Who wins that question? Ted Cruz, barely, with 13%. Cruz was the original anti-establishment choice in the race, but he’s trailing badly as a first choice at 9%. Scott Walker does slightly better on the second-choice question with 9% for fourth place. He’s not out of the running, in other words, but he’s losing ground in this populist groundswell — at least for now.

It’s not just Republicans in Iowa who are feeling the anti-establishment fervor. A Des Moines Register poll published Saturday shows Iowa Democrats are feeling the Bern:

Liberal revolutionary Bernie Sanders, riding an updraft of insurgent passion in Iowa, has closed to within 7 points of Hillary Clinton in the Democratic presidential race.

She’s the first choice of 37 percent of likely Democratic caucusgoers; he’s the pick for 30 percent, according to a new Des Moines Register/Bloomberg Politics Iowa Poll.

But Clinton has lost a third of her supporters since May, a trajectory that if sustained puts her at risk of losing again in Iowa, the initial crucible in the presidential nominating contest.

This is the first time Clinton, the former secretary of state and longtime presumptive front-runner, has dropped below the 50 percent mark in four polls conducted by the Register and Bloomberg Politics this year.

It’s still early, and historically voters tend to “date” populist candidates far more than they “marry” them.