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 bloody shirt of 9/11. A Clinton television ad  torn right from Karl Rove’s 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 can’t stand the heat, get out of the kitchen,” the narrator intoned.