On Wednesday, Mother Jones ran an article making a shocking claim: more Americans have been killed by conservative terrorists than by Islamic terrorists since September 11, 2001. “While America has been fixated on the threat of Islamic terrorism for more than a decade, all but a few domestic terror plots have failed,” the article explained. “Between September 11, 2001, and the end of 2012, there were no successful bomb plots by jihadist terrorists in the United States …. [R]ight-wing extremists killed 29 people during those 11 years.”

But is it true?

The Mother Jones piece is based on a study by the New America Foundation and Syracuse University’s Maxwell School. But that study routinely labels non-right-wing murderers right-wingers, and labels basic crimes involving murder “terrorist attacks.”

Here is their complete list of “rightwing terrorist attacks,” with number of killed in parentheses:

Realistically speaking, then, there were a grand total of 2 killings over the last 12 years by “right-wing extremists.”

The study lists just four Islamic terrorist attacks in that period:

The list does not include the Beltway snipers (11 killed, including a 2002 shooting of a Tucson man); Mohammed Ali Alayed, who slashed a Jewish friend’s throat after reportedly undergoing a religious revival; Mohammed Reza Taheri-azar, who used his SUV to attack students (9 injured) at the University of North Carolina at Chapel Hill in revenge for “the deaths of Muslims worldwide”; the list goes on. The list also does not include honor killings (the equivalent to the George Tiller assassination), or random murders involving Muslims (the equivalent of half the items on the “rightwing terrorist attacks” list.

Naturally, the study does not bother to list left-wing terrorists.

The attempt by the left, including Mother Jones, to minimize the threat of Islamic terror inside the United States and to maximize the threat of “right-wing extremism” is all too obvious. By using the label “right-wing extremism” to apply to everything from neo-Nazis to anarchists, the left seeks to smear the right, the same way it smeared the right with the shooting of Gabrielle Giffords.

The truth remains that the Islamist threat in the United States is very real – and that only the dedication of law enforcement has stopped substantially more Islamist attacks. After the Boston Marathon bombings that killed three and wounded well over 170, only a truly philosophically perverse publication would claim that right-wingers are actually more of a threat to public safety than Islamists.

Ben Shapiro is Editor-At-Large of Breitbart News and author of the New York Times bestseller “Bullies: How the Left’s Culture of Fear and Intimidation Silences America” (Threshold Editions, January 8, 2013).