It was an extraordinary night for Obama, though, one Hillary Clinton predicted would never happen. She said some time ago that she would have the nomination wrapped by Super Tuesday. Instead the "Obama effect" stalled her progress, perhaps fatally.

Last night she won important victories in California, New York and Massachusetts, but he took Missouri and Connecticut. Obama also won more states, 13, and leads Clinton in pledged delegates, his campaign claims. As his campaign pointed out, he was strong on all points of the compass from the Deep South to the Midwest and Far West.

In a sign that the Clinton campaign is low on money, she wants to debate him every week for the next four weeks (an alternative to paying for saturation advertising).

"On the Democratic side, my sense is we're going into two, three weeks now which will probably favour Obama," says David Gergen the wise owl on CNN and former Clinton adviser.

Obama’s speech last night was once again sensational – seen by his supporters as yet another move to generate momentum while hitting lots of the familiar themes. But it also appealed to those Americans still on the sidelines. It was delivered to an audience that was mostly white and seems in no doubt that he will win the nomination. They believe that they are part of an unstoppable movement for change.

Obama's campaign point out that they dominated all the states that held caucuses, an indication of  how energised his supporters are. Time is now on his side as he heads into a relatively friendly series of primaries – Louisiana & Nebraska on Saturday followed by the "Washington Beltway" primaries on Tuesday, DC, Maryland & Virginia. It is a long stretch to Clinton friendly Pennsylvania on 22 April. In the money wars he is also ahead with $32m raised in January alone. Clinton raised good money - $13.5m – but only 3% of Obama donors have reached their upper limit of $4,600.

Broadly speaking her advantage remains women and Hispanic voters, but white men - who had backed Edwards - voted Obama, as did young voters.

Hillary Clinton’s campaign still has the advantage of being backed by party stalwarts and her name recognition. Last night they called her victory in Massachusetts "the upset of the night", but it seems his message of "change" is winning out over her message of experience. He praised Hillary campaign last night but then went in for the kill saying that change will never come from a campaign that is more in hock to Washington lobbyists even than the Republicans'.

Obama’s campaign manager David Axelrod believes the nominee will only emerge when it is clear that one candidate has the momentum (he of course thinks it's going to be Obama) rather than when a magic number of delegates is reached.

The campaign message is very strong. They talk about their "movement", which saw 3,000 show up at a caucus in Kansas. Axelrod says: "He is energising the party and expanding the electorate, not just to win an election but to build a governing coalition."