At this stage in the race for the White House, no one has any doubts anymore that moving back into her “home” of eight years is Hillary Clinton’s overriding motivation. She spends more time denigrating and “misspeaking” about her opponent, Barack Obama, than about issues, or Republican candidate John McCain; to the point that Americans are becoming fed up with the nasty tone of the battle between the two Democratic candidates.

According to a new poll, 50% of Americans (as well as 50% of Democrats) now believe that the campaign has become too nasty – so nasty, in fact, that 20% of those polled say that they will not vote for Clinton in November if she is nominated.

Obama, meanwhile, finds himself in a tricky situation. After promising a new style of politics, he can hardly engage in mudslinging the way Clinton does. If he turns too negative, voters will accuse him of flip-flopping on his promise, and Clinton will doubtless let people know that Obama’s new way of politics eerily looks like the old; that is, her approach to political campaigning.

But how many more punches and low blows must Obama take before he is willing to speak up for himself? Following Clinton’s win in Pennsylvania, political pundits and observers have begun to urge Obama to take the gloves off and go after Clinton at full blast. Both he and his campaign are resisting these calls for getting tough.

While the two candidates battle it out, the Democratic party is slowly falling apart. Some high-level Democrats have called on Clinton to drop out of the race for the sake of the party, and more recently, one Slate.com blogger has suggested that Obama should be the one withdrawing from the race, so that he can run and win in 2012.

This is very bad advice. Obama’s moment is now – not only for himself, but also, more crucially, for America. America needs a president like Obama now, not in 2012, when McCain would have had four years to drive the country even deeper into the hole - yes, McCain, because the only way to prevent McCain from becoming president is to pair him off against Obama, for Clinton does not stand a chance against the war veteran.

The nastiness, however, is not limited to the Democratic side. McCain has intimated that Obama is a candidate “favored by Hamas” and that Obama would be a president serving Hamas and terrorist interests, rather than American ones. McCain, who is a respected “senior citizen” and liked, or at least tolerated, by both Republicans and Democrats, has certainly hit a low point in the campaign with his remarks, which have tinfoil written all over them. In the far-fetched department, his comments are about as logical or reasonable as if he had claimed that Obama had arrived on earth 47 years ago in a space ship and had been raised by a family on a farm in Kansas.

Among Republicans, this will not harm him much, even though many, and a growing number of, Republicans have been slipping over into the Obama camp. Nor will this open up a gaping rift in the Republican party, because their candidate has been nominated, and now they are all determined to close ranks.