There is a lot of talk that Senator Hillary Rodham Clinton is now fated to lose the Democratic nomination and should pull out of the race. We believe it is her right to stay in the fight and challenge Senator Barack Obama as long as she has the desire and the means to do so. That is the essence of the democratic process.

But we believe just as strongly that Mrs. Clinton will be making a terrible mistake  for herself, her party and for the nation  if she continues to press her candidacy through negative campaigning with disturbing racial undertones. We believe it would also be a terrible mistake if she launches a fight over the disqualified delegations from Florida and Michigan.

The United States needs a clean break from eight catastrophic years of George W. Bush. And so far, Senator John McCain is shaping up as Bush the Sequel  neverending war in Iraq, tax cuts for the rich while the middle class struggles, courts packed with right-wing activists intent on undoing decades of progress in civil rights, civil liberties and other vital areas.

The Democratic Party must field the most effective and vibrant candidate it possibly can. More attack ads and squabbling will not help achieve that goal. If Mr. Obama wins, he will be that much more battered and the party will be harder to unite. Win or lose, Mrs. Clinton’s reputation will suffer more harm than it already has.