According to the U.S. State Department, "terrorism" is defined as "Premeditated, politically motivated violence perpetrated against noncombatant targets by subnational groups or clandestine agents, usually intended to influence an audience."
If we accept this definition, we must also accept that domestic terrorism exists inside the United States, but the media and our government rarely call it terrorism, despite their own definition, because the following examples of domestic terrorism are products of the domestic far right (Dare we call it the Republican base?)
Here are some examples just off the top of my head. I'm sure there more that don't immediately come to mind.
Eric Rudolph, bomber of abortion clinics and the Olympic Games, and identified with the militant and racist Christian Identity Movement. A top-selling t-shirt seen in the area of Rudolph's time as a fugitive from the law said "Run, Rudolph, Run."
Timothy McVeigh, Oklahoma City bomber and murderer of 168 people, and avid quoter of right-wing fantasy novel The Turner Diaries, in which scrappy white separatists bravely revolt against an evil Jewish, multi-cultural, gun-confiscating, totalitarian government.
Unknown (and perhaps un-pursued) Persons, mailer of anthrax and murderer(s) of five people, who targeted two Democratic Senators and the evil "liberal" media. And who can forget Freeper and wannabe anthrax mailer Chad Castagana who mailed fake anthrax to "drama queen" Kieth Olbermann.
William J. Krar, Judith Bruey, and Edward Feltus, white supremacists and anti-government wannabe terrorists who were foiled and caught with significant quantities of weapons, explosives, and chemical agents including a sodium cyanide bomb. (What? You never heard about it? Me neither!
Link)
And for good measure:
National Security Watch: 60 right-wing terror plots foiled, a U.S. News and World Report story from July 2005.
Well, golly. Sorry, you bed-wetting freepers. As much as you strenuously try to link terrorists and liberals together in your minds, the fact remains that terrorism is a product of fundamentalist and violent thinking, most commonly a trait of the right-wing, this includes those in the Islamic world, and especially in the United States.