I would imagine it's a rarity.
But I would guess someone in their early-to-mid 20s who joined "the force" straight out of college, with a BA in something like sociology, psychology, or--gods forbid--criminal justice (*e-giggles*) from a traditional brick-and-mortar school. And will probably only be a beat cop for several years, before leaving LE entirely to do something completely different, like going into academia or grad school.
Ironically, these are probably the best coppers you would want interacting with the general American public, especially in the ghettos around the blacks. I have zero experience working with American civilian police, but the closest parallel to what you're thinking of is, say, German Polizei. They can crack skulls as a last resort if need be, but otherwise overall pleasant, friendly, and diplomatic public servants.
Nowadays, yes. Back in the 1990s-2000s, yes, there was still white male cops who still voted Democratic; hell a lot of them are still registered Democrats but too lazy to change to unaffiliated or Republican....
But I am sure white Boston cops still vote Democratic, or else Stephen Lynch and others would have lost.
The job has become more hyperpolarized than Darryl Gates and Rudy Giuliani did to it.
You need white cops like this guy in the video below, to fix relations in the black community....
https://www.youtube.com/watch?v=GIany51XuuI&t=102s