Now that Senator Hillary Clinton has suspended her campaign for the United States presidency and given her unqualified endorsement of Senator Barack Obama, we can now brace ourselves for a vicious campaign of character assassination against Mr Obama by his political rivals.

In fact, since Saturday, when Senator Clinton urged her supporters to use their energy, passion and strength to put Senator Obama in the White House, news services in the USA have been focusing on the likely content of the anti-Obama advertisements or Internet chatter that will be published across that country in the run-up to the presidential elections in November.

The storm created over the association between Mr Obama and his minister of 20 years, the Rev Jeremiah Wright, will definitely be revived, given the successful job already done by the Republicans of painting Rev Wright as a bigot and bitter critic of America who has accused the US Government of creating AIDS.

So too will criticism of the Rev Michael Pfleger, the firebrand white Catholic priest who, in a sermon at Mr Obama's church recently, mocked Senator Clinton while accusing her of expecting to win the Democratic party nomination because she was white.

Although Rev Pfleger apologised and Mr Obama condemned the remarks and resigned from the church, the senator, it is said, is likely to face questions about his relationship with the reverend.

We are also being told of Mr Tony Rezko, a businessman who has helped raise campaign money for Senator Obama and who was convicted last week on 16 of 24 counts involving mail fraud, wire fraud, money laundering and aiding and abetting bribery, even though the charges have no connection whatsoever to Mr Obama.

The name William Ayers, with whom Senator Obama has a very limited relationship, has also been raised for the fact that Mr Ayers, now a university professor and member of Chicago's intellectual establishment, was, 40 years ago, a member of a radical group that claimed responsibility for a series of b****ings, including at the Pentagon and US Capitol.

The man regarded as Senator Obama's political godfather, Mr Emil Jones, president of the Illinois Senate, has also been thrown into the mix, with the US media already alleging that he has a reputation for "steering state money to a few favoured institutions, including some that employ his relatives", even though they admit that the political styles of both men are different.

So there will be no shortage of fodder for Senator Obama's critics who want to undermine his historic bid for the presidency. How the candidate himself and his campaign team respond to each criticism as they are raised will, we believe, have a significant bearing on the outcome of the vote in November.

His success in the presidential race will also rest heavily on the ability of the Democratic party's leaders to unite its supporters by healing the wounds created by the bruising primary contest.

To her credit, Senator Clinton has already started that process with her speech in Washington on Saturday. "I endorse him and throw my full support behind him," she declared. "Today as I suspend my campaign, I congratulate him on the victory he has won and the extraordinary race he has run. I ask of you to join me in working as hard for Barack Obama as you have for me."

Her endorsement is significant for the fact that she won approximately 18 million votes in the primaries with women accounting for a solid bloc of that support.

The Democrats now have a mere four months to heal the rift in their party and win over the undecided. Whether they will be able to do so, only time, and the results in November, will tell.