Donald Trump continues to lead Republican primary polls. Above, he participates in the first prime-time presidential debate hosted by Fox News and Facebook Aug. 6, 2015, in Cleveland. Getty Images/Chip Somodevilla

WASHINGTON -- Donald Trump isn’t going to be knocked out of first place as easily as some of the pundits had expected. Despite a heavily criticized debate performance -- and the ensuing feud with Fox News’ Megyn Kelly -- Trump still leads the Republican primary field in Iowa.

The real estate mogul and reality-TV star placed first with 17 percent in a new Suffolk University poll, conducted after the Thursday night debate among GOP presidential hopefuls in Cleveland, which was broadcast on Fox News and co-sponsored by Fox and Facebook. And the pollster attributes Trump's continued success in part to the size of the GOP field, which includes 17 candidates and is considered the deepest bench the Republicans have ever had.

“It appears that Donald Trump’s lead is strong so long as the number of active opponents remains above a dozen,” said David Paleologos, director of the Suffolk University Political Research Center, in Boston. “If the Republican field were winnowed down to five or six candidates, Trump’s 17 percent probably wouldn’t be enough to win in Iowa, as polling indicates that his further growth has limitations. The long-shot candidates staying in the race help keep Trump on top — at least for now.”

Trump came under a firestorm of criticism -- again -- after Thursday night’s debate, the first for 2016 Republican presidential hopefuls and drew unprecedented attention. Trump was combative with event moderator Megyn Kelly, and he refused to apologize. The next day he fed the fire while talking to CNN, with words that seemed to suggest that Kelly’s menstrual cycle was to blame for her "attitude."

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Despite his Megyn Kelly remarks, Donald Trump is still leading the Republican field of U.S. presidential candidates, an online poll indicates. Mandel Ngan/AFP/Getty Images

Although it didn’t hurt him with voters, the debate didn’t appear to do Trump any favors either. Of those who watched the debate, he was tied with Wisconsin Gov. Scott Walker at 14 percent, with Florida Sen. Marco Rubio close behind at 11 percent. But for those who didn’t watch, Trump was still on top, winning 21 percent of their support.

Republicans who were polled and watched the debate reported they thought the most impressive performances came from Rubio and neurosurgeon Ben Carson.

“In the absence of a debate, Trump’s lead widens because he swallows up the political oxygen, but when that oxygen is spread out more evenly in a debate, it breathes life into the other candidates, and the race gets closer,” said Paleologos.

The rest of the field is still struggling to catch up with Trump. The Suffolk poll found Walker in second place with 12 percent, despite the fact that before Trump exploded on to the scene he was long seen as the candidate to beat in Iowa. In third place was Rubio at 10 percent, followed by Carson at 9 percent.

Donald Trump Presidential Candidate Profile | InsideGov

Tied for fifth place with 7 percent each were Texas Sen. Ted Cruz and former Hewlett-Packard CEO Carly Fiorina -- who saw her numbers increase dramatically after her performance in Thursday’s second-string early debate was roundly praised as a success.

Trailing far behind in Iowa is former Florida Gov. Jeb Bush, at 5 percent, despite his second-place finish in national polls. Ohio Gov. John Kasich received 3 percent. The only other candidates to exceed 1 percent were former Arkansas Gov. Mike Huckabee, Sen. Rand Paul of Kentucky and New Jersey Gov. Chris Christie, all tied at 2 percent.