That's because the radio and TV airwaves are jammed with ads from both candidates and outside groups in the drive to Tuesday's Pennsylvania Primary.

I was barely across the Mason-Dixon Line when I heard the first ad from Obama on the radio, which was followed by more Obama ads sprinkled with a few from Clinton.  Meanwhile, my Blackberry was in overdrive.

"New Obama Ad Responds to Last Minute Clinton Attack Ad" said Team Obama.

"Newspapers call Hillary Clinton's negative attacks the "old politics."  And now, in the final hours, she's launched the most misleading and negative ad of the campaign," the ad began, wrapping up with, "Eleventh hour smears, paid for by lobbyist money: Isn't that exactly what we need to change."

Both sides accused the other of running a negative ad war.

"Sen. Obama has flooded airwaves, radio, phone lines and mailboxes with negative and false attacks against Hillary," said Clinton Communications Director Howard Wolfson.

While Obama fought back against an ad that ridiculed his claim that he doesn't take money from lobbyists, the Clinton camp cried foul over an ad that targeted Hillary's health care plans.

"Announcer: He couldn't answer tough questions in the debate. So Barack Obama is making false charges against Hillary's health care plan," said the ad.

Both sides said the other was also using misleading robo calls.

"The Clinton campaign is using robocalls to tell Pennsylvanians Obama is not the candidate for them," said Obama spokesman Hari Sevugan.

On the stump, Obama accused Clinton of following through on a "kitchen sink" strategy featuring nothing but negative attacks.

Another email from the Clinton camp:  "Hillary Clinton Responds to New Attack Ad Released Today by The Obama Campaign."

Another email from the Obama camp: "Obama Campaign Reaction to Clinton Attacks on Dems Behind Closed Doors."

You get the picture.