This is the famous “Daisy” ad… the first modern TV attack ad. It was put out by the LBJ campaign against Barry Goldwater in 1964.
This is the “Willie Horton” ad taken out by the National Security PAC (on behalf of the Bush/Quayle campaign) that did tremendous damage to Michael Dukakis in 1988. See my article “Do you think this flag makes my dogma look fat? Reagan’s Legacy” for a sense of the times for why this ad was particularly effective.
And who can forget this hit on Obama by the Clinton campaign in the 2008 primaries.