Jim Sleeper has some insights into whether a "monstrous crime" always "stands on its own." He recalls a connection he once made between "the 1993 shooting rampage of deranged black loner Colin Ferguson against 25 white Long island Rail Road passengers, six of whom died, and a black radio station, WLIB":
Ferguson was an avid listener to the station, whose morning talk show hosts were spewing so much racial bile at that time, including metaphorical death threats against white journalists, that Nat Hentoff wrote station owner Percy Sutton to ask if he'd ever thought what would happen if some deranged loner took the rhetoric seriously. Sutton didn't respond and the rhetoric rolled on...
In 1985, the black poet Julius Lester noted presciently, nine years before Colin Ferguson shot those commuters, that violent rhetoric such as Louis Farrakhan's at that time was "subtly but surely creating an atmosphere in America where hatreds of all kinds will be easier to express openly, and one day, in some as yet unknown form, those hatreds will ride commuter trains into the suburbs. By then it will be too late for us all."
(Lester's comments and mine are on the second item on the pdf I've linked here.)
Ferguson's deed underscored the extra-legal truth that -- again -- some psychotics are tuned in more acutely than the rest of us to a society's subliminal signals and that, if those undercurrents of fear and hatred are surfaced by impresarios of ethno-racial grievance, the deranged may be only the first to act on them. That truth was also bared in the lethal rage of former Brooklyn resident Baruch Goldstein, who massacred 29 Palestinians at prayer on the West Bank only months after Ferguson's rampage.
My own view, as of the current evidence, is that Loughner was first a foremost a mentally ill person, but that some shards of far right ideology had entered his paranoid brain. I wonder if readers can track down comments on Ferguson by some of those on the right now denying any conceivable connection between acts of violence and incendiary rhetoric.