You're right.
Most conspiracy theorists seem to come from the left...
Liberals are actually KKK sympathizers who intentionally keep blacks and other poor people dependent on government benefits so they can control their votes.
Global warming is a conspiracy among thousands of scientists to take away our freedom and institute socialism.
Those who criticize the tactics of the war on terror are Al Qeda supporters.
Obama is a secret Muslim who is not a real citizen.
Illegal aliens are voting in large numbers.
Muslims in America plan to institute Sharia law.
Most of the world's two billion Muslims want to take away our freedom and force us into being Muslims.
Environmental laws are a way to impose socialism.
Environmentalists want to exterminate humans for the environment.
Liberals support eugenics.
Gay marriage is a plot to destroy marriage.
Liberals prefer Muslims to Christians.
Gays and Atheists are using the schools to impose their ideology and recruit members.
Saying "Happy Holidays" is part of the conspiracy to destroy Christmas and Christianity.
These are all right wing conspiracy theories without a shread of truth. Just from the last thirteen years. The only somewhat popular left wing conspiracy theory is the 9/11 one. No proof on that one IMO, but it is true that the neo-cons hoped for an terrorist attack so they could get involved in theh middle east militarily. (see the Plan for a New American Century)