As his once-buoyant campaign for the Republican presidential pick begins to show signs of fragility, Rudy Giuliani was himself struck with illness, checking himself into hospital with flu-like symptoms.
The former New York Mayor began feeling unwell while in Missouri on Wednesday. It was only when he was aboard a plane in the evening bound for New York, his home base, however, that he turned around for hospital.
A spokeswoman said Mr Giuliani, 63, made the decision after talking to doctors on the phone. He spent the night at the Barnes Jewish Hospital in St Louis.
Mr Giuliani was discharged from hospital last night and resumed his trip back to New York. In a statement Katie Levinson, Mr Giuliani's communications director, said: "Mayor Giuliani is being released from Barnes Jewish Hospital with a clean bill of health.
"Doctors performed a series of precautionary tests and the results of all the tests were normal. The mayor is heading back to New York this afternoon and he continues to be in high spirits."
In 2000, Mr Giuliani was forced to give up campaigning in New York against Hillary Clinton for a US Senate seat after being diagnosed with prostate cancer. His withdrawal helped clear the path for Mrs Clinton's victory. Mr Giuliani has since declared himself to be in good health.
The sidelining however brief of Mr Giuliani comes amid further evidence that among Republicans especially, the nomination race remains wide open. Officials say it has been decades since party members have gone into the primary season without any clear front-runner to gather around.
There are now less than two weeks before the Iowa caucuses, when members of both parties begin whittling down the candidates to select the final two who will face each other in the election. After the Iowa caucuses on 3 January, the New Hampshire primary follows just five days later.
The pressure is therefore on all of the candidates as they try to close the deal with voters before their attention drifts away to turkey and Christmas dinners. However, Mr Giuliani may be feeling the heat more than anyone. A new NBC-Wall Street Journal poll published yesterday showed him in an exact tie nationally with Mitt Romney, the former Governor of Massachusetts. With 20 per cent each, meanwhile, the two men were only marginally ahead of Mike Huckabee, the former Arkansas Governor, whose campaign has been turbo-boosted in recent days.
It suggests a dramatic slippage for Mr Giuliani, who through December has been hit with a barrage of unflattering media coverage both about his past marriages and business dealings, including those with his former New York Police Commissioner, Bernard Kerik, recently hit with federal fraud charges.
Mr Giuliani had the comfort of leading nearly every national poll through the autumn and usually by fat margins. But the new poll shows him slipping 13 points since the last survey in November. Mr Huckabee, meanwhile, has shot up in the rankings after being only in single digits before.
Mr Giuliani has shifted his focus in recent days away from Iowa and New Hampshire to states that will vote some weeks later, notably Florida on 29 January and a flurry of states, including Missouri, New York and California, on 5 February.
It is a risky and highly unusual strategy. It may have been forced upon Mr Giuliani, however, after a blitz of television advertising in New Hampshire earlier this month failed to lift his ratings there. He has never considered himself competitive in Iowa.
Questioned about his strategy on Wednesday, Mr Giuliani said that losing one or two early races need not be critical.