How will Donald Trump react to his slip in the polls?

reporting from Washington —  When Republican presidential candidates gather for their third debate on Wednesday, Donald Trump will once again stand at center stage, but for the first time, he won’t be the undisputed leader. How he handles that could reshape the way voters perceive him.

Ever since Trump’s presidential bid caught fire, Republican strategists have wondered how he would react if he began to slip in the polls he so loves to cite. As a candidate, he wields “loser” as a favored epithet and, in marked contrast to most politicians, talks frequently about his standing.

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Trump can still accurately brag about his lead nationally and in several early-voting states — though a CBS/New York Times poll released Tuesday showed the retired neurosurgeon Ben Carson ahead nationally by a narrow margin, others still have Trump on top. In Iowa, however, at least four polls released over the past several days show Trump seriously trailing Carson in the state, which holds the first contest in the race for the presidential nomination.

Trump’s loosened grip on the lead comes at an important time in the campaign for him and the rest of GOP field. Increasingly, voters who once believed Trump could not win the nomination now view the New York billionaire as a plausible — even likely — nominee. However, many Republicans harbor reservations about him and his often-bombastic personality. Watching how he handles an adverse moment, particularly against a rival who enjoys a highly favorable image among Republicans, could prove significant for GOP voters.

In a town hall aired Monday on NBC’s “Today” show, Trump said he doubted the accuracy of polls showing him behind. “I think I’m winning in Iowa,” he said. “I don’t believe I did fall behind.”

He also insisted he has dealt with adversity in the past, reaching for an example that, from another candidate’s mouth, might be politically fatal.

“It’s not been easy for me. I started off in Brooklyn. My father gave me a small loan of a million dollars,” he said, noting that he repaid the loan with interest.

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But while Trump may disparage the polls that show him trailing, he has clearly begun taking Carson seriously as a rival, criticizing him on both substantive and personal grounds.

He has zeroed in on Carson’s proposal for replacing existing government health programs with medical savings accounts.

Carson “wants to abolish Medicare,” Trump said on Twitter. While Republicans tend to back smaller government, Medicare is supremely popular with the majority of Republican voters, who are generally older than the rest of the electorate. That’s particularly true of the voters who form the core of Trump’s support, non-college-educated, blue-collar Republicans who like his outspoken nationalism and share his skepticism about immigration and free trade.

Carson, in two television interviews on Sunday, denied he would do away with Medicare.

Instead of eliminating anything, Carson said, he would “provide people with an alternative.” But in interviews with Fox News and NBC’s “Meet the Press,” he failed to clarify how he would pay for his plan without diverting money from existing government programs, which he conceded was his original proposal.

Trump has also accused Carson of being “low energy” — an accusation he previously threw at Jeb Bush — and has raised questions about Carson’s Seventh-day Adventist faith.

“I’m Presbyterian,” Trump said at a recent campaign rally in Florida. “Boy, that’s down the middle of the road, folks, in all fairness. I mean, Seventh-day Adventist, I don’t know about. I just don’t know about.”

Carson said Sunday that he would not get “into the mud pit” with Trump on personal issues.

Carson’s rise to the fore in Iowa has come about largely because of his strong support among evangelical Christians. A poll released Monday by Loras College in Iowa showed Carson beating Trump by 18 percentage points among those who identified as evangelicals but only 2 percentage points among those who did not.

Among Iowa Republican voters who said they attended church services at least weekly, Carson led Trump 37% to 11%, the poll found. By contrast, Trump led 43% to 15% among the much smaller group of voters who said they seldom or never attended church.

In the past, the backing of evangelical voters has been enough to propel some candidates to victory in the state’s caucuses, including former Gov. Mike Huckabee of Arkansas in 2008 and former Sen. Rick Santorum of Pennsylvania in 2012. Neither of them was able to do as well in other states where evangelicals constitute a smaller share of the party’s voters.

Similarly, Carson remains behind Trump by as much as 20 percentage points in other early-voting states such as New Hampshire and South Carolina. The bigger threat to Trump may be that tangling with Carson could worsen his image among voters who already have doubts about his personality.

Those concerns could be heard last week at a focus group in Indiana, sponsored by the Annenberg Public Policy Center, where a dozen Republican voters talked about their choices. Virtually all expressed distaste — even disgust — for professional politicians, including Republican elected officials whom they blamed for failing to accomplish the goals for which they were elected.

“We’re out to clean house,” said Marenda Babcock, a 60-year-old freelance writer. America “doesn’t want a career politician,” she said.

“We have no faith in politicians,” chimed in Lorinda Phelps, a 30-year-old photographer.

Trump, by contrast, seemed fresh and honest, several said.

“Sometimes there isn’t time to pussyfoot around,” said John Couch, a 50-year-old self-employed party planner, explaining why he thought Trump’s directness could help the country.

But doubts about the brash New Yorker came quickly to the surface as veteran pollster Peter Hart, the group’s moderator, asked participants to cite adjectives to describe Trump. Disturbing, shoot from the hip, divisive, impulsive, self-serving, hothead, the group members answered.

Asked at the end of the session to choose a single candidate to whom they would like to send a message, Phelps chose to offer Trump a piece of advice that spoke for many: “You’ve got great policies,” she said, “but tone it down.”

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