In fact, he is up three points since last month, and nearly half of his supporters - 46 percent - said they made up their minds, which also outstrips the rest of the Republican presidential field, reports CBS News correspondent Nancy Cordes.
At a nighttime rally in New Hampshire, Trump dismissed the rest of the GOP pack and repeated his debunked claim that he saw thousands of Muslims celebrating in New Jersey on Sept. 11, 2001.
"I think they're weak, generally. You want to know the truth but I won't say that," he said. "I saw it and a lot of people saw it."
As proof, he cited a newspaper article, and his campaign adviser cited clips from New York station WCBS and MTV in 2001 - neither of which showed a large celebration.
"There has been no jubilee in the streets, nobody thinking this is a great or glorious idea," a local official said in the MTV interview.
In Dubuque, Iowa, former Florida Gov. Jeb Bush accused Trump of saying things he knows aren't accurate for shock value.
"He's gone too far, he's showing a lack of seriousness, as being capable of being president," Bush said.
Bush is stuck at five percent in the latest Quinnipiac poll, while Sen. Marco Rubio and Sen. Ted Cruz are both up three points from last month.
Nonetheless, Bush set his sights on Democratic frontrunner Hillary Clinton, and her comments to "CBS This Morning" co-host Charlie Rose on fighting ISIS.
"In terms of thousands of combat troops like some on the Republican side are recommending, I think that should be a non-starter," Clinton told Rose.
Bush said he'd leave all options on the table.
"This is all political for her. This should be viewed as a national security threat because that's exactly what it is," Bush said. "If you start by creating preconditions with America's leadership, you're not going to have followers, it's plain and simple."
Looking to generate some buzz of his own, Bush implied at a campaign stop that he'd likely pick a woman as his vice presidential nominee.
Several Republican women have been mentioned recently as possible vice presidential picks, including South Carolina Gov. Nicki Haley, New Mexico Gov. Susanna Martinez, and New Hampshire Sen. Kelly Ayotte.