Newt Gingrich, whose career seemed dead and buried just weeks ago, has capitalised on Herman Cain's exit to establish a huge lead in the early voting states that could decide the Republican White House race.
A poll in the Washington Post put him 15 points ahead of Mitt Romney, the nominal front-runner whose victory has been seen as a given by political analysts.
Gingrich has similarly large leads in two of the other three states that hold presidential primaries next month and is steadily closing the gap in the fourth - Romney's once-impregnable stronghold of New Hampshire.
The stunning rise of the former House Speaker has banished any chance that the demise of Cain, who effectively ended his bid at the weekend, would see support reluctantly rally around Romney.
Instead, Gingrich has seized the momentum in Iowa ahead of the January 3 caucus that kicks off the primary season.
The Washington Post/ABC poll gave him 33 per cent support among likely caucus voters in Iowa, with Romney and Texas congressman Ron Paul both on 18 per cent.
Gingrich has a similar 15-point lead in South Carolina, where Texas governor Rick Perry is third.
In Florida, where Cain was strong, Gingrich has a 25-point gap on Romney, while the latter's once-massive lead in New Hampshire has been halved to about 15 points.
Moreover, Gringrich may soon be endorsed by Cain, a friend and fellow Georgian.
The turnaround in his fortunes reflects not just activists' dissatisfaction with Romney but also a string of solid debate performances in which the veteran Washington politician has shown fluency on the issues and much less arrogance than in the past.
His priorities have changed as well. With his support now soaring, Gingrich now needs the money and organisation to match.
On Tuesday he was not in Iowa or New Hampshire but in Manhattan for fundraisers with wealthy donors, and the now obligatory call on Donald Trump - mogul, reality television host, and seeming Svengali of Republican presidential politics.
That last function appals several party strategists, who note that Trump - a leader of the "birther" campaign against Barack Obama and who has talked about his own White House bid - will return to the limelight when he hosts a candidates' debate days before Iowa votes.
Ari Fleischer, a former George W. Bush spokesman, called the debate "an invitation to a circus".
The immediate question, however, is whether Gingrich will outlast Michelle Bachmann, Perry and Cain before him, who each briefly soared to the top of the polls as the "anti-Romney" candidate before coming to grief.
Many observers predict the former Speaker will self-destruct as he has done not infrequently in his controversy-studded career.