The following letter was submitted to the Washington Post in response to "Beware the data on American right-wing violence" (May 23) To the Editor: In “Beware the data on American right-wing violence,” Megan McArdle admits that far right violence is a problem, but insinuates it isn’t necessarily a bigger problem than other kinds of ideological violence. She offers no evidence but tries to make her case by second-guessing ADL’s annual reports on extremist-connected…