Generally we discard 9/11 from such discussions as it blows death toll comparisons out the window. Going post 9/11 stays both relevant to current times and removes the absolute worst events in both cases (Ok city, and 9/11).

Doing comparisons without these cases we get similar numbers for both factions within some wide margin of error. Looking at this from a per capita perspective though we have Muslim Americans that make up around 1% of the population by my googling having a similar terrorism death toll as the 32% of the population that is right wing white Americans (white Americans being 64% of the population. This would make that faction 32 times more dangerous per capita than the white right wing.