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US Repulican presidential candidate Mitt Romney addresses the Newspaper Association of America in Washington, DC, April 4, 2012.

What constitutes a negative political ad, and what is simply informational? Where is the line in the sand? Mitt Romney’s primary campaign pulled a TV ad that slammed Rick Santorum for his losing senate campaign in Pennsylvania, right after Santorum suspended his campaign to be at the hospital bedside of his daughter, Bella.

The Romney ad would also have started running today. Despite the longstanding assumption that negative ads work in political campaigns (remember the “Daisy Girl” ad from Lyndon Johnson’s campaign against Barry Goldwater in 1964?), attack ads remain a tricky political tool. Most Americans say they dislike them - but does that mean they're not effective? The Swift Boat ads were fatal to John Kerry's presidential campaign in 2004. Yet the ads can also boomerang back to their source.

WEIGH IN:

Are attack ads really more effective than ads praising a candidate’s accomplishments? Was the Romney campaign’s ad more “forgiveable” before Santorum’s announcement?

Guests:

Tom Del Beccaro, Chairman of California Republican Party

Todd Gitlin, professor of journalism and sociology, Columbia University

Lisa Graves, executive director of the Center for Media & Democracy