Wasn't the last time in 1968 in Chicago, during the Democratic National Convention? The "Days of Rage,"
And once again, Mad goes half a century back to try and spin reality. You seem to have forgotten the more recent OKC bomber (hardly a leftie) or the Reverend Jesus H Koresh, a gun lovin' Texas boy.
During the 1980s, more than 75 right-wing extremists were prosecuted in the United States for acts of terrorism, although they carried out only six attacks during the decade. In 1983, Gordon Kahl, a Posse Comitatus activist, killed two federal marshals and was later killed by police. Also that year, the white nationalist revolutionary group The Order (also known as the Brüder Schweigen or Silent Brotherhood) robbed several banks and armored cars, as well as a sex shop; bombed a theater and a synagogue; and murdered radio talk show host Alan Berg.
McVeigh stated it was retaliation for the government's actions in Ruby Ridge and Waco. McVeigh attended Michigan militia group gun shows.
Eric Rudolph executed a series of terrorist attacks between 1996 and 1998. He carried out 1996 Centennial Olympic Park bombing -- which claimed two lives and injured 111 -- with the aim of to cancelling the games, claiming they promoted global socialism. Rudolph confessed to bombing an abortion clinic in Sandy Springs, an Atlanta suburb, on January 16, 1997; the Otherside Lounge, an Atlanta lesbian bar, on February 21, 1997, injuring five; and an abortion clinic in Birmingham, Alabama on January 29, 1998, killing Birmingham police officer and part-time clinic security guard Robert Sanderson, and critically injuring nurse Emily Lyons.
According to data compiled by the New America Foundation, since the 2001 September 11 attacks, right-wing extremists have committed at least eight lethal terrorist attacks in the United States, resulting in the deaths of nine people. According to the Federal Bureau of Investigation, between January 1, 2007 and October 31, 2009, white supremacists were involved in 53 acts of violence, 40 of which were assaults directed primarily at African-Americans, seven of which were murders and the rest of which were threats, arson and intimidation. "These were treated as racially motivated crimes rather than political acts of violence, i.e. terrorism."[33