Rush Limbaugh has stated several times that the assassination of John F. Kennedy ushered in the era of modern liberalism. Liberals back then just couldn't handle the fact that the assassin was Lee Harvey Oswald, a communist who lived for awhile in the Soviet Union. So they attempted to blame America and the "rightwing" for Kennedy's assassination.
In the current update of that attitude, liberals hate to see radical Muslims blamed for acts of terrorism. The prefer and wish for such acts to have been committed by somebody they can associate with conservatives. The latest example of this is Samuel L. Jackson who flat out expresses his disappointment in The Hollywood Reporter that the culprit in the San Bernardino shootings wasn't "some crazy white dude" rather than who it really was, a radical Muslim couple.
Jackson says he empathizes with innocent Muslim-Americans who have fallen under the veil of suspicion because a few other people who share their religion have committed atrocities against their countrymen: "When that thing happened in France, we were sitting there going, 'Oh, my God, these terrorists!' And I can't even tell you how much that day the thing that happened in San Bernardino — I was in Hawaii — how much I really wanted that to just be another, you know, crazy white dude, and not really some Muslims, because it's like: 'Oh, shit. It's here. And it's here in another kind of way.' Now, okay, it happened on an Army base and it happened somewhere else. But now? It's like they have a legitimate reason now to look at your Muslim neighbor, friend, whatever in another way. And they become the new young black men."
Jackson's attitude about what groups he hopes are guilty of acts of terrorism instead of who really do commit terror is reflected by many liberals such as former New York Mayor Mike Bloomberg a few years ago who mentioned the usual favored suspects that he believes placed a car bomb at Times Square. Of course, the eventual culprit turned out to be a radical Muslim.