Reading the WSJ's excellent reporting on Loughner's participation in various computer game forums, the same patterns emerge. He's obviously mentally disturbed, and the content of his addled mind is best described by the WSJ:

The postings exhibit fixations on grammar, the education system, government and currency, which some friends and acquaintances have described separately in the days since the attack. They are peppered with displays of misogyny.

As the Dish has noted from the get-go, he doesn't seem very political except in a broadly paranoid sense, which is why the core question that remains unanswered is why he decided to try to assassinate his congresswoman. But we do get weird diversions into currency and this:

One post alluded to the Fifth Amendment, which aims to protect citizens against the government abusing its power in legal proceedings.

The most important thing in understanding him is mental illness. There is no evidence of any formal political connection to any group or ideology. My reason to pause and leave this question still marginally open is his expression of such intense paranoia, references to government illegitimacy, and suspicion of government currency. There's paranoia on far right and far left, and then there's the paranoia in which that distinction seems moot (and is some strange conflation of both).

By the way, it appears that he gave up smoking pot a while ago; and it also appears that he lived large swathes of his life as an avatar online.

Update: We still don't really know why Loughner targeted Giffords, as I wrote above, but I didn't mean to imply there was evidence of a connection. This is not dispositive but it is relevant:

Bryce Tierney, a friend of alleged shooter Jared Loughner tells Mother Jones magazine that Loughner had always had a grudge against Rep. Gabrielle Giffords (D-Ariz.), and that it was a missed voice mail message Loughner left on his phone that led him to believe Loughner was involved in the mass shooting. In the message Loughner said, "Hey man, it's Jared. Me and you had good times. Peace out. Later."

Tierney, described as "an old and close friend with whom he had gone to high school and college" in the Mother Jones report, said that Loughner had repeatedly called Giffords a "fake," and that his hatred of Giffords intensified after he attended a campaign event where he posed a question to the congresswoman. According to Tierny, Loughner's question was, "What is government if words have no meaning?"

"He said, 'Can you believe it, they wouldn't answer my question,' and I told him, 'Dude, no one's going to answer that,'" Tierney recalls. "Ever since that, he thought she was fake, he had something against her."