It’s not the show of patriotism that provides safety. Clarifying here: it’s the fact that none of the politically left-leaning folks in the Seattle are going to wear an American Flag, and the only folks who DO choose to display the flag are conservatives. It’s definitely not that conservatives require one to display a show of patriotism lest you abandon your safety. It’s that cyclists are generally a strongly anti-conservative group in many parts of the Seattle area, on average, and so there is a feeling among conservatives that cyclists harbor ill feelings towards them.
The areas I mentioned are somewhat conservative outcroppings of a largely left-leaning area.
This behavior probably wouldn’t be present in areas where it’s assumed that any of the cyclists are conservative. My time in North Carolina, TN, AZ, and UT has been worlds different than in the conservative pockets of western WA, just north of Seattle. I have spent roughly the same amount of time riding in each locale, for reference.
And I have spoken with Washington State conservatives who have admitted to hating cyclists on the road and would bet money that they’d agree with my sentiments here. It’s not that they love patriotism. It’s that they don’t see the danger in harassing a faceless liberal on a bike on a road they feel like they shouldn’t be riding on.
100% agree. When I’ve ridden in more broadly conservative areas, the treatment like I am “the enemy” is much less harsh if it exists at all. In TN, you’re totally right, it was usually 18-20somthing males in cheap vehicles doing the buzzing.
Utah, though in a conservative area, was one of the friendliest places on the planet to ride, for Michelle and I. Arizona’s pretty good too, though by comparison to Arlington, WA, anything is joy. Okay, no that’s not true. Louisiana was rough. We were public enemy number 1 on my one day in Louisiana. Even a cop pulled us over to tell us to get off the road there. lol.
Irony… I drive a big diesel motorhome and have tested the same wave and smile on identical-looking trucks and get loads of happy waves from similar F-250-type folks (full disclosure, I’ll probably buy an F-250 as next vehicle) who treat me and Michelle like we’re public nuisances when we’re on the bike.
That’s probably further evidence that it’s not about the patriotism, but the fact that these folks who will endanger cyclists’ just view them as “not one of us.” Not a good reason… obv, so please just take this as clarification!
@darrellcraig, Commenting here in case it’s helpful in any way. My wife and I have had far less negative experience in the rural gravel areas in the aforementioned locales where our treatment on paved roads has been dangerous. I think something about being off the paved roads (insert “my taxes paid for this road”) and generally being closer in physical proximity on gravel has actually made the treatment of my wife and I, much better on narrow forested gravel roads. Something about being able to see the whites of someone’s eyes is disarming, I think, but I am not black, so can’t speak specifically to that experience. Based on some of the angry toothless folks I’ve had fun encounters with on the road, truthfully, I suspect that in some of those areas where half the population views cyclists as a public nuisance that shouldn’t be on the paved roads…I’d get even more frequent buzzes with dually tires and beater trucks if I were black. Totally hazarding a guess here.
Related anecdote: in those conservative areas in WA, if Michelle wears pink or otherwise makes it more obvious that she is a woman, she is generally treated more safely. Fewer close calls for sure. If I’m solo or if I’m obscuring the view of the driver to see that Michelle is indeed a woman (I’m 6’1 210 and often drafting her due to fitness discrepancy), we get buzzed more than ever because now we’re definitely just a couple liberal recreational cyclists blocking the road during rush hour and are therefore public enemy number one.
As always, this is my n=1. 
I hope it provides useful context.