NEW YORK - Republican presidential candidate Donald Trump has surged past Senator Ted Cruz in Iowa, ahead of Monday's caucuses, while former Secretary of State Hillary Clinton, seeking Democratic Party's nomination for president, is clinging to a razor thin lead over Senator Bernie Sanders, a leftist, a new poll shows.

Trump garnered the support of 28 percent of Hawkeye State voters compared to 23 percent for Cruz, according to the final Des Moines Register/Bloomberg Politics poll released Saturday afternoon. But Cruz, the ultraconservative who had been leading in Iowa, is still more popular and respected than Trump, according to the latest poll.

“The drill-down shows, if anything, stronger alignment with Cruz than Trump, except for the horse race,” Ann Selzer, the pollster for the Iowa Poll, said. Florida Senator Marco Rubio was in third place with 15 percent, while former neurosurgeon Ben Carson captured 10 percent. Clinton is edging Sanders by three percentage points – 45 percent to 42 percent.

The poll emerged hours after Trump, the Republican front-runner, made a final pitch to evangelical Christians. In a video posted to Facebook on Saturday, Trump thanked evangelicals for their support - vowing to “never let you down.”"I really appreciate the support given to me by the evangelicals," Trump said.

"They've been incredible. Every poll says how well I'm doing with them." Trump then held aloft a worn Bible, which he said his mother had given to him "many years ago." "In fact, it's her writing right here," he added, flipping to the first page of the book. "She wrote the name and my address and it's just very special to me."

This is not the first time the Republican front-runner has used the Bible as a prop on the campaign trail.

In September, Trump waved the same copy of the book while giving a speech at the Values Voters Summit hosted by the Family Research Council in Washington, DC. Trump has also repeatedly named the Bible as his favourite book - though he has often faced criticisms for his inability to name his favourite Bible verses. In the past, white evangelical voters have made up nearly half of Republican primary voters and caucus-goers. And in Iowa, conservative Christians make up an outsized portion of likely caucus attendees.