Few would doubt that Mr Obama is now on that list.
The cutting comparison came as he launched a last-ditch push to win over Democrats in Iowa, who vote on Thursday in their caucuses, the first stage of the presidential nomination process.
|Barack Obama on the campaign trail in Iowa, where he launched blistering attacks on his rival, Hillary Clinton|
Now, his lofty rhetoric about hope and change is laced with sharp, sarcastic jabs at Mrs Clinton and her husband Bill, who have sought to paint him as a naïve lightweight who doesn’t have the stomach for a fight.
At a Des Moines rally that drew in more than 1,000 people despite freezing weather, Mr Obama abandoned his previous timidity and, while not mentioning her by name, aimed barbs straight at the former First Lady. "We can’t afford a politics that’s all about terrorism and ripping people down rather than lifting a country up," he said. "We can’t afford a politics based on fear that leaves politicians to think the only way they can look tough on national security is to vote and act and talk just like George W Bush."
Mr Obama is locked in a three-way struggle with Mrs Clinton and John Edwards in Iowa. Polls, which are notoriously unreliable in the Midwestern state, indicate Mrs Clinton might have edged just ahead in the past week.
Bill Clinton, now campaigning in Iowa for his wife every day, has raised the spectre of another September 11 style attack and stated that only Mrs Clinton had the experience to deal with a terrorist atrocity.
Mr Obama blasted back by suggesting that this was reminiscent of the tactics of Mr Bush and Vice President Dick Cheney in 2004 and amounted to "using 9/11 as a way to scare up votes".
The slap at Mrs Clinton — who voted to authorise the Iraq war — was no accident. Yesterday, at a smaller rally in rural Perry attended by about 250 people, Mr Obama used almost exactly the same words.
When asked by The Daily Telegraph about the increasing sharpness of Mr Obama’s words, David Axelrod, his chief strategist, said: "I don’t think they were sharp. I think they were well chosen."
He added that Mrs Clinton was "100 per cent known" but "70 cent or more of voters in this state have consistently chosen other alternatives so there’s obviously a market for something different out there.
The Obama campaign has been angered by the negative attacks from Clinton operatives, most notably the suggestion — widely seen as a racial smear — that he had been a cocaine dealer. Clinton supporters have also circulated emails suggesting Mr Obama is a radical Islamist.
The Illinois senator took on Mr Clinton directly, disputing the former president’s contention that a vote for Mr Obama would be to "roll the dice" on America’s future. "The real gamble," he thundered, "is to keep on doing the same things with the same folks over and over again and expecting something different." A central argument of the Obama campaign is that electing the former First Lady would mean a Bush or a Clinton running the country for 24 years without interruption. The Clintons, the Illinois senator said, were Establishment creatures who resented someone new to Washington.
He lampooned their view of him as: "We need him in Washington longer to stew him and season him a bit and boil all the hope out of him so he smells just like every other politician." Mrs Clinton’s repeated use recently of the word "change" — the theme of the Obama campaign since the start — was also mocked.
"This change thing must be catching on because I notice now suddenly everybody’s talking about change. ‘I’m for change, me too, I want to change things, I’m a change person’. "That’s good. We want everybody to be for change. But you have to ask yourself now with basically four days left is who can best deliver change."
Any prospect of a Clinton-Obama ticket for the presidency and vice-presidency has evaporated but the Illinois senator’s supporters are convinced he can do better than the second slot.
"We have to get rid of the dynasties in this country," said Carol Hofmann, celebrating her 64th birthday by going to the Obama rally in Des Moines. "We’ve had the Bushes, we’ve had the Clintons.
"The candidate people see as the front runner is very, very divisive and I think she’s dangerous. I voted for Bill Clinton. She wouldn’t have been elected a senator without him. She sure wouldn’t be running for president if she wasn’t married to him." She added: "She probably has a list a mile long of people she would like to stick the knife into."