The average American in 2008 was not walking into a synagogue and murdering people. Let's not pretend that far-right extremism is something other than what it actually is.
This is just incorrect. Bolt action and muzzleloaded rifles are both extremely common and not semiautomatic.
That being said, "semiautomatic" is usually a useless scare-word thrown in by people who have no clue what they're talking about.
That period was also heavily dominated by Islamophobia in the US with firebomb attacks on Islamic Centers and random brown people getting assaulted and called "terrorists".
Heck, a mere 4 days after 9/11 happened a Sikh was shot for being mistaken as an Arab Muslim due to his turban [1]. Which actually makes no sense but hate rarely does.
[0] https://en.wikipedia.org/wiki/United_States_Holocaust_Memori...
[1] https://en.wikipedia.org/wiki/Murder_of_Balbir_Singh_Sodhi
Are these people average Americans? [0]
No offense, but this sounds a lot like the argument how Trump supporters are allegedly just a "loud minority", a claim that's factually disproved not just by results from the public votes of two presidential elections, but the fact that he won one of them and only barely lost the other one.
Where does the "average American" fall in that context? Is there even an "average" when the only two valid political choices have become distilled down to a superficial "We are not the other party" forcing everybody to pick between two allegedly completely opposing sides?