By Lesley Curwen
BBC News, Washington
Pressure is growing on one of the United States' top Republican politicians to step down because of allegations of sleaze and influence-peddling.
DeLay is majority leader in the House of Representatives
Congressman Tom DeLay is under scrutiny for questions about illegal fund-raising, where money came from for foreign trips he made, and links with a controversial lobbyist who is under investigation.
Little-known outside the US, he is a major fund-raiser for President George W Bush and runs a network of huge political influence.
Mr DeLay has denied all wrongdoing and says he is the subject of a witch-hunt. But others see his troubles as evidence of an ethical crisis in US politics
Jim Barnes, of the left-leaning National Journal magazine, said: "He is known as a very shrewd but hard political player, hence his nickname 'The Hammer'.
"He does have a record of what some people would say are ethical lapses."
Three of Mr DeLay's former aides have been charged with illegal fundraising.
A Congressional ethics committee has reprimanded him three times for what it calls objectionable behaviour. And there is the question of his travels.
It is alleged money for a trip to Britain, which included golfing in Scotland was arranged by Jack Abramoff, a political lobbyist and friend of Mr DeLay, now being investigated for alleged corruption.
Another DeLay trip, to South Korea, was paid for by a foreign organisation, which is illegal under Congress rules.
His critics have launched TV adverts showing a man trying to wash blood off his hands.
One such ad comes from the left-wing Campaign for America's Future (CAF) which is urging him to give up his leadership on Capitol Hill.
The CAF's Ellen Miller sees Mr DeLay as a symbol of a wider ethical decline in politics.
"We feel that all of the ethical charges that have been lodged against him have proved him to be unfit to lead Congress.
"He runs the institution in a way that is highly undemocratic; he takes money from corporate lobbyists and does their bidding... And we feel that he is an embarrassment to the US Congress and the country."
It has also emerged that Mr DeLay's wife and daughter were paid a total of $500,000 over four years by his campaign committees - not illegal but it has raised eyebrows.
Washington is alive with rumour about DeLay
Mr DeLay has called the allegations against him "fiction and innuendo".
At the moment he can still count on the support of President Bush and party bigwigs like Morton Blackwell, a member of the powerful Republican National Committee.
"There has not been a single allegation in all these left-wing attacks on him of any occasion when he broke the House rules or the law.
"The only fire underneath all that smoke is the left-wing's burning hatred of Tom DeLay."
A lone Republican Congressman, Chris Shays, has called for Mr DeLay to stand down and even the right-wing Senator Rick Santorum advises Mr DeLay to face up to his detractors.
"I think he has to come forward and lay out what he did and why he did it and let the people judge for themselves."
'Alive with rumour'
During a briefing to more than 40 reporters at his office in the Capitol, Mr DeLay spoke for half an hour but flatly refused to tackle questions about his behaviour.
He says he will only answer to the ethics committee in Congress.
But that committee is not working - because Democrats and Republicans on it are not speaking to each other in a quarrel over rule changes.
According to Jim Barnes, the DeLay story shows how power can corrupt.
"The Republicans criticised these kinds of ethical lapses when the Democrats controlled Capitol Hill.
"Now it raises the spectre of was there some kind of hypocrisy here on the Republicans' part."
Washington is alive with rumour about one of its most powerful politicians.
For the moment Tom DeLay shows no signs of surrender.
If he were toppled, it could damage his party and shake Americans' faith in the integrity of their leaders.