The Pennsylvania campaign, which produced yet another inconclusive result on Tuesday, was even meaner, more vacuous, more desperate, and more filled with pandering than the mean, vacuous, desperate, pander-filled contests that preceded it.

Voters are getting tired of it; it is demeaning the political process; and it does not work. It is past time for Senator Hillary Rodham Clinton to acknowledge that the negativity, for which she is mostly responsible, does nothing but harm to her, her opponent, her party and the 2008 election.

If nothing else, self interest should push her in that direction. Mrs. Clinton did not get the big win in Pennsylvania that she needed to challenge the calculus of the Democratic race. It is true that Senator Barack Obama outspent her 2-to-1. But Mrs. Clinton and her advisers should mainly blame themselves, because, as the political operatives say, they went heavily negative and ended up squandering a good part of what was once a 20-point lead.

On the eve of this crucial primary, Mrs. Clinton became the first Democratic candidate to wave the *lo**y shirt of 9/11. A Clinton television ad torn right from Karl Roves playbook evoked the 1929 stock market crash, Pearl Harbor, the Cuban missile crisis, the cold war and the 9/11 attacks, complete with video of Osama bin Laden. If you cant stand the heat, get out of the kitchen, the narrator intoned.

If that was supposed to bolster Mrs. Clintons argument that she is the better prepared to be president in a dangerous world, she sent the opposite message on Tuesday morning by declaring in an interview on ABC News that if Iran attacked Israel while she were president: We would be able to totally obliterate them.

By staying on the attack and not engaging Mr. Obama on the substance of issues like terrorism, the economy and how to organize an orderly exit from Iraq, Mrs. Clinton does more than just turn off voters who dont like negative campaigning. She undercuts the rationale for her candidacy that led this page and others to support her: that she is more qualified, right now, to be president than Mr. Obama.

Mr. Obama is not blameless when it comes to the negative and vapid nature of this campaign. He is increasingly rising to Mrs. Clintons bait, undercutting his own claims that he is offering a higher more inclusive form of politics. When she criticized his comments about bitter voters, Mr. Obama mocked her as an Annie Oakley wannabe. All that does is remind Americans who are on the fence about his relative youth and inexperience.

No matter what the high-priced political operatives (from both camps) may think, it is not a disadvantage that Mr. Obama and Mrs. Clinton share many of the same essential values and sensible policy prescriptions. It is their strength, and they are doing their best to make voters forget it. And if they think that only Democrats are paying attention to this spectacle, theyre wrong.

After seven years of George W. Bushs failed with-us-or-against-us presidency, all American voters deserve to hear a nuanced debate right now and through the general campaign about how each candidate will c****at terrorism, protect civil liberties, address the housing crisis and end the war in Iraq.

It is getting to be time for the superdelegates to do what the Democrats had in mind when they created superdelegates: settle a *lo**y race that cannot be won at the ballot box. Mrs. Clinton once had a big lead among the party elders, but has been steadily losing it, in large part because of her negative campaign. If she is ever to have a hope of persuading these most loyal of Democrats to come back to her side, let alone win over the larger body of voters, she has to call off the dogs.