Unless they made some specific political statement I missed in the show Kahn and Minh would also probably vote at least center right, because they're fleeing a shithole communist country in Laos, even if Minh's father is a general.
Minh and Khan are social climbers and if the Wasonasons (crappy spelling/the family Kahn and Minh were forever sucking up to due to them being wealthier and more successful) were voting Hillary, they'd vote Hillary or at least go through the elaborate Kabuki theater of voting Hillary then voting Trump and lying that they did and then become ultra-paranoid about being found out. Or reacting to Trump's anti-immigration stance post election by way of a massive case of guilt/regret over helping elect Trump.
That said, I do think that if KOTH was around today, Judge would probably feel the need to do a pro-immigration episode and use the Kahn and his family being harassed for being Southeast Asian by Trump supporters to bash Trump, complete with Bobby and Hank explicitly coming to their defense and giving end of episode speeches rebuking Trump. And maybe, even a Manbearpig sized groveling apology for the episode towards the end of the series, where Judge took a huge fucking shit on Critical Race Theory via having the school be forced to hire a CRT advisor who basically turned all of the kids at school against each other and manipulated Bobby into turning a school fair stye fun day into a struggle session, where instead of playing in a bouncy house and other kids games, everyone was forced to admit to being racist and berated and insulted into they cried and agreed to say whatever th CRT advisor demanded they say to stop the bullying.
I can see Hank hating Trump personally (crude New York businessman) but holding his nose for him anyway and after 2020 he'd 100% be onboard with him. Hank voting for Beto let alone being 'all in' for him? Lmao
I think Hank would be anti-Trump but get ostracized for it because everyone would think he's for Hillary (especially if Peggy was a huge Hillary booster). He'd begrudgingly warm up to Trump but be one of those Republicans who hate Trump but hates the Democrats even moreso, which leads to a mid-life crisis and Hank going third party/apolitical.
Like the Simpsons' Homer, he's been Flanderized over the years so that he objects to the smallest and pettiest of things now that he used to not care about, and seems a bit nastier, but that's just because the jokes are running out after all the years... he's a study in why the "You kids get off my lawn!" guy becomes the way he does.... he'll become cantankerous one day, but never violent or loony, that's just not who he is.
I'd argue that Hank wasn't flanderized so much as wholesale retooled.
People forget that Hank was a right cunt asshole in the first couple of seasons of King of the Hill. And someone who was right only because of the fiat of the writer.
Fans hated Hank and even Fox didn't like Hank, leading to the famous bit where they suggested Hank be killed off and go the single mom route with Peggy and Bobby, which led to the famous two part episode where Megalo Mart exploded and Judge trolling everyone by doing a promo where Bobby/Peggy/Luanne would move to LA the following season, which he backed off on when he realized that Fox thought he was being dead serious.
As it stands, post-Megalo Mart explosion Hank was radically different from pre-explosion Hank in that he was far more mellow and autistic and there was a lot of work humanizing Hank and tacitly justifying his behavior via Asperger syndrome and his fucked up homelife as a kid (abusive father, mother who ultimately allowed Cotton to run rampant and retreated to her miniature collection room whenever Cotton went on the rampage, Hank's well being be damned).
Of course, that had the side effect of needing someone else to stir up drama, which is why Peggy got hit with the Flanderized stick HARD. So she became an insufferable bitch who thought she was smarter than everyone else and who constantly needed Hank to save her ass.