WASHINGTON (AFP) - American conservatives watching and sometimes wincing as "Mama Grizzly" Sarah Palin threw her support to Donald Trump were left wondering whether their movement to reclaim the White House in 2016 had received a shot in the arm - or to the heart.
Conservative icon Palin, the 2008 vice presidential nominee, delivered the endorsement heard round the US political world in a rambling, sarcastic and occasionally improvisational speech Tuesday with Republican frontrunner Trump at her side.
It might pay critical dividends for the braggadocious celebrity billionaire as he seeks conservative credibility in the run-up to the February 1 caucuses in Iowa, where Americans cast the first votes in the nominating process.
But several conservative pundits and analysts warned that it could also shred efforts to install a core conservative as the next US president.
If Palin helps Trump win, "emotionalist nationalistic populism will have officially - perhaps temporarily - supplanted principled, policy-driven, limited-government conservatism as the dominant strain within the American right wing," wrote commentator Guy Benson on conservative opinion website Townhall.com.
Palin has been one of the movement's controversial luminaries over the past decade. She has retained the loyalties of many core conservatives, which could translate into votes for Trump as he faces a stiff challenge in Iowa from Tea Party favourite Senator Ted Cruz.
"We need someone new... who can bust up that establishment, that can make things great again," Palin told the Trump crowd.
"Media heads are spinning," she said in a mocking tone. "This is going to be so much fun."
US media indeed have had a field day with Palin's appearance in the Trump spotlight.
"I'm with stupid!" blared the New York Daily News, depicting the pair on its front page.
Securing Palin's endorsement when he did may have been a stroke of genius for Trump, who managed to steal the thunder from a surging Cruz in a state critical for the senator's nomination chances.
But several conservative pundits and strategists have sounded off about Palin's endorsement, warning that it could backfire on a movement that has struggled to define itself within the parameters of a 2016 presidential race that has thoroughly upended convention.
"OMG. Sarah Palin has gone rogue," William Kristol, founder and editor of The Weekly Standard magazine, tweeted after Palin's speech, in which she used foul language, mocked President Barack Obama as a "weak-kneed" coward, and evoked disturbing terrorism imagery.
Palin has praised Trump for months, and she could act as an important surrogate for him on the campaign trail.
But is she helping Trump harness the anger that has boiled over within the Republican base, or merely grabbing more self-promoting attention?
The endorsement has fuelled speculation that Palin, a former governor of Alaska, might be offered a position in a Trump cabinet, should he win the White House.
"She could play a position if she wanted to," Trump told NBC on Wednesday.
Critics panned Palin for backing a political novice whom they accuse of once supporting government bailouts and abortion rights and donating to Democrats.
"I couldn't disagree with her more," disillusioned conservative talk show host Glenn Beck fumed on Facebook. "Maybe the press was right about her."
Conservative personality Tucker Carlson, founder of The Daily Caller, was left unconvinced that Palin would help Trump's primary chances.
"She's not that impressive, she squandered this great political capital she had eight years ago and hasn't achieved really anything since - and also she gives disjointed speeches," he told Fox News.
After losing in 2008, Palin kept a hand in politics while turning to business endeavours, including reality television and a stint as a pundit on Fox News.
Her endorsement of Trump appears to draw a line between core conservatives and those in the more reactionary, anti-establishment camp.
Even Cruz, who lost out to Trump for her endorsement, acknowledged Palin is capable of having an impact.
"She can pick winners," Cruz has said, a wry reference to her endorsement of him in his underdog 2012 Senate race.