US:Former New York mayor Rudy Giuliani has taken the first step towards a 2008 presidential run, with opinion polls putting him ahead of all other candidates from either party.
Mr Giuliani faces a formidable challenge in seeking the Republican nomination, however, as his liberal views on abortion and gay rights put him in conflict with social conservatives.
The former mayor, whose leadership of his city after the attacks of September 11th, 2001, made him a national hero, is campaigning as a foreign policy hawk who can win support from independents and some Democrats.
He supports president George Bush's decision to send more troops to Iraq, although he acknowledged this week that there is no guarantee the operation will be successful.
"Whatever happens in Iraq - success or failure, success will help us in the war on terror. Failure will hurt us. But the war's still going to go on. They're still going to want to come here and kill us," he told Fox News.
Mr Giuliani, who said in 1989 that he would give his daughter money for an abortion if she needed it, has not retreated from his pro-choice stance but hopes that conservatives will look beyond the issue to judge him on his leadership qualities.
"Where I stand on abortion is I oppose it, I don't like it, I hate it. I think abortion is something that is a personal matter that I would advise somebody against.
"However, I believe in a woman's right to choose. I think you have to ultimately not put a woman in jail for that. I think ultimately you have to leave that to a disagreement of conscience," he said.
When he separated from his second wife in 2001, Mr Giuliani moved in temporarily with two gay friends and he supports gay civil unions, although he opposes gay marriage.
His supporters believe that Mr Giuliani's tough approach to foreign policy and the leadership he showed after September 11th, 2001, will outweigh conservative concerns about his liberalism.
His fundraising base in New York should ensure that he can raise his target of $100 million by the end of this year and he has started assembling an experienced campaign team.
Close scrutiny of his record as mayor could raise embarrassing questions, however, notably about his relationship with former police chief Bernard Kerik, who pleaded guilty last year to improperly accepting gifts from a construction firm with links to organised crime.
Mr Giuliani's consulting and lobbying firm, Giuliani Partners LLP, has faced criticism for representing gambling and energy companies and opponents have accused him of profiting from 9/11 through lucrative speaking engagements.