Meh, partially plausible - tailgaters seldom respond nicely to their targets slowing
and tapping their brakes (I'm stating a fact, not justifying the behavior) - partially obvious fictional embellishment (the Trump flags)

.
Three
Cool Story Bros out of a possible five.
On weekdays, I typically see 1-4 jerky tailgaters. It's called commuting. Given the voting habits of Santa Clara County, there's a 75% chance with each that they're a Hillary/Biden-voting jerky tailgater. Being a jerk is a humans characteristic, not something peculiar to a particular political party.