Hillary Clinton's victory in the Pennsylvania primary was just enough to keep her presidential bid alive, but her opponent Barack Obama still leads in both the delegate count and the popular vote.
Democratic primaries still have to be held in Indiana, North Carolina, Nebraska, West Virginia, Kentucky and Oregon in May while the last two primaries, in Montana and South Dakota, will be held in June. So we can expect a fight to the bitter end, which of course, can only favour the Republican candidate, John McCain.
Because most of the state Democratic primaries do not have a 'winner takes all' electoral system, the number of pledged delegates are awarded to each candidate in proportion to the percentage of the popular vote received.
Mrs Clinton, who won Pennsylvania with 54 per cent of the popular vote, was awarded 80 delegates, while Obama got 46 per cent of the vote and 66 delegates.
A total of 2,025 delegates is needed to secure the nomination and it is highly unlikely that this threshold will be reached before the Democratic Party convention in August, which means that the still uncommitted 'super delegates' - senior party officials, 309 of whom have not yet endorsed either of the candidates - will decide who the candidate is to be only then.
So far Senator Obama has a total of 1,714 delegates (1,481 pledged and 233 super delegates) while Senator Clinton has 1,589 delegates (1,331 pledged and 258 super delegates).
The remaining 309 super delegates will probably choose the party nominee in August, as it is mathematically impossible for a candidate to be chosen during the remaining primary elections - unless, of course, there are a series of highly unlikely landslide victories by either candidate.
Although Clinton is still trailing Obama, she will point to her victories in the large states such as Pennsylvania, New York, California, Texas and Ohio as proof that she is the best candidate to defeat Senator McCain in November.
The presidential election has a 'winner takes all' system and whoever wins a state takes all its Electoral College votes. That means that a victory in the large states - which have by far the highest number of Electoral College votes - could easily translate into an electoral victory. Mrs Clinton will surely be making this point as she lobbies the super delegates for their support.
A number of political observers, including some Democratic Party grandees, have urged Senator Clinton to step down in the interest of party unity and to endorse Senator Obama.
After her victory in Pennsylvania, however, Mrs Clinton made it clear that she has absolutely no intention of stepping down, and she has certainly proved that she is a determined fighter.
One point that is often made - and I think it is a valid point - is that should Obama be denied the nomination by the super delegates even though he would have won the popular vote (he is currently beating Clinton by 600,000 votes), then that could split the party, lead to a huge resentment among Obama supporters and look anti-democratic. It could also hand victory to the Republicans on a silver plate.
So, who has the best chance of retaking the White House for the Democrats and defeating the Republican candidate? The Pennsylvania vote showed Mr Obama had the backing of black people, the young, university educated voters and most importantly, independents.
Mrs Clinton, on the other hand, won the support of females, the white working class, high school graduates, registered Democrats and the elderly.
These coalitions are also more or less in place nationally and have to a certain extent polarised the Democrats - so it is not easy to say who can best unite the party and who can beat Mr McCain. Furthermore, if the contest goes all the way to the summer convention, will the losing side rally to support the nominee?
The fact that Senator Obama enjoys wide support among independents and Senator Clinton does not, coupled with the fact that he is leading in the popular vote probably points to Mr Obama standing a better chance of defeating John McCain in November.
On the other hand, Mrs Clinton recently made some inroads into Mr Obama's national lead, and exit polls in Pennsylvania showed that Mrs Clinton won the support of six out of 10 voters who made up their mind a few days before voting.
It seems that Senator Clinton's portrayal of herself as being more credible than her opponent on economic issues - the number one priority for voters - as well as on national security issues - where for example she spoke about 'obliterating' Iran if it attacked Israel - has paid off somewhat.
Mr Obama also suffers from an 'elitist' label - in the same way as failed Democratic presidential candidates Al Gore and John Kerry did. This, however, does not mean he cannot win if he is the nominee in November. It simply means that he must try harder at identifying himself with the average voter and his or her everyday concerns.
On balance I feel that Obama probably has a better chance than Clinton of defeating John McCain in November, because of his appeal to people outside his party, and because he is widely regarded as the candidate of change.
However, the Republican candidate cannot be written off, especially if Mr McCain successfully distances himself from George Bush. Furthermore, Mr McCain is also widely respected among independents.
The longer the democratic contest carries on, the more difficult it will be for the Democratic nominee to win in November.
Perhaps the super delegates should now consider throwing their weight behind Mr Obama. This would wrap up the nomination and allow the contest between the two parties to start in earnest.