"This is going to be so much fun".

But she's remained an active commentator on political issues throughout the Obama era - and has gradually grown more and more hostile to the GOP establishment that she feels so badly mistreated her. All of this has naturally culminated in her endorsement of the ultimate anti-establishment candidate, Donald Trump.

"No more pussy-footing around", she said, adding that Mr Trump would allow the military do its job and destroy the Islamic State group. "Would the left ever, would the DNC [Democratic National Committee] ever come after the front-runner and her supporters?" John McCain in his 2008 bid for the White House.

Mr. Trump was at 32 percent in the Opinion Savvy/Augusta Chronicle poll, followed by Mr. Cruz, Texas Republican, at 18 percent and Mr. Bush at 13 percent.

Trump is scheduled to hold campaign rallies in Norwalk, Iowa, and Tulsa, Okla., on Wednesday.

The endorsement by Palin, now a fixture on cable TV, is a major pickup for Trump, who has been struggling to maintain a share of the lead in Iowa ahead of the February 1 caucuses as Sen. In fact, Cruz himself was more conciliatory in a tweet Tuesday, saying he "will always be a big fan" of Sarah Palin's no matter what she decides about the 2016 race.

She's been a less prominent figure in recent years as other outsider, conservative candidates - such as Cruz - have emerged as favorites of the party's grass roots.

Trump in July mocked Palin's 2008 running mate, Sen. There haven't been a lot of people wondering, where's Sarah Palin; why aren't we hearing more from her? She said she'd like the Ministry of Energy post.

Trump is a real estate billionaire from New York City who has taken to vigorously insulting politicians in both parties while demonising Muslims and some Mexicans, an unusual approach in United States presidential politics. "It sort of denies Ted Cruz any chance to get back on offense".

Palin's Trump nod is seen as a snub to conservative Senator Ted Cruz, who is neck and neck with Trump in Iowa and running second to him nationally.

But some rally-goers at Trump's event Tuesday evening said they weren't sure whether Palin's support would help Trump. Several referenced what they saw as her poor performance as a vice presidential candidate.

"He hasn't supported renewable fuels and I believe it would be a big mistake for Iowa to support him", Governor Branstad said.