The old dude being a Trump supporter doesn't automatically make it politically motivated. Possible for sure - Americans do have a history of killing Nazis - but this could also be something like texting while driving and running the dude over due to sheer obliviousness.
The suicide makes me think it's something like the latter... if the driver was out for blood, actually getting it wouldn't push him to kill himself.
...at least we're down a Nazi. ¯\_(ツ)_/¯