Last Iowa poll: Trump leads Cruz by 5 percent

DES MOINES, Iowa, Jan. 31 (UPI) -- Donald Trump is leading the GOP pack in the final poll before the Iowa caucuses on Monday with the support of 28 percent of likely caucus-goers to 23 percent for Ted Cruz and 15 percent for Marco Rubio.

The Des Moines Register/Bloomberg Politics poll also showed Trump leading by a much bigger margin among first-time caucus-goers with 35 percent to Cruz's 19 percent. A big turn-out on Feb. 1 could mean that Trump wins by a big margin.

But the poll also showed that if the GOP race were limited to just Trump and Cruz, 53 percent would prefer Cruz as the nominee compared to 35 percent who would choose Trump.

The survey of 602 likely Republican caucus attendees had a margin-of-error of plus or minus 4 percent. Neurosurgeon Ben Carson, who was leading in Iowa in late 2015 but whose support has since dropped dramatically, came in fourth in the poll with 10 percent support. All other candidates were in the single digits.

"Donald Trump could win Iowa," Stuart Stevens, a GOP strategist, told The Des Moines Register. "But he has little room for error. He is almost no one's second choice."

Only 7 percent of likely caucus-goers picked Trump when asked about their second choice. Rubio is the top second choice with 20 percent support, followed by 17 percent for Cruz and 11 percent for Carson.

About 9 percent of likely Republican caucus-goers are still undecided, joining the 45 percent of those polled who said they could be persuaded to change their minds ahead of Monday's Iowa caucuses.