Wesley and DougR, ANYONE who uses really vitriolic "annihilate-them" rhetoric needs to turn it down. And, no, it's not always those on "the right" that use it. Back in 1968, a speech was given at the American Psychological Convention in San Francisco by (IIRC) Kathleen Cleaver, wife of Eldridge Cleaver, in which she repeatedly proclaimed "The gun is the answer!"   I found that sort of perspective and rhetoric disturbing even back then, and she was definitely "leftist" in her political leanings.   

But there is an important difference between simply using strong rhetoric to highlight one's opposition to a candidate or policy or law (e.g., calling a policy "atrocious" or even "criminal") and saying things like "I'd like to blow his brains out" or that citizens should "be armed and dangerous" because it's time for a "revolution." There's also a big difference between calling out someone because of something they've actually proposed or done (e.g., initiated the occupation of another country or suspended habeas corpus or authorized unwarranted wiretaps or voted to raise/lower taxes) and spewing hatred towards someone because of false or unfounded allegations (e.g., saying that "Obamacare" involves "death panels" or that Obama "wants to take your guns away" or that today's Democrats are "communists." There's a huge difference between saying that you think so-and-so should be investigated or indicted and tried in legitimate courts and calling for so-and-so's murder or assassination.

Some well-known talk show hosts, bloggers, columnists, and political "strategists" HAVE talked/written of wishing they could kill people they disagree with (e.g., Michael Moore, Nancy Pelosi, Barack Obama, etc.)   I have heard one or two liberal talk show hosts say they "hate" the far right wing or label people like Mitch McConnell or Dick Cheney or Bill O'Reilly "Today's Worst Person In The World" but never heard any of them say they would like to kill them or see them assassinated or. I've never heard any of them suggest that guns or bombs or any sort of violence should be used against people just because their policies and politics differ.   

Let us not make the mistake of lumping all hyperbole & sarcasm & strongly worded allegations or objections together. And, please, let's not propose that everyone refrain from using emotionally charged or blunt, confrontive language when it fits.   We don't need to revert to saying things like "Holding people indefinitely in GITMO without affording them legal counsel or even charging them with any crime isn't a very nice thing to do."

But it's not valid to say that really vitriolic rhetoric, especially when it evokes images of dealing with opponents by bloodshed, does not contribute to things like shooting rampages, just because we can't draw a direct single-causal line between the rhetoric and such a violent attack.