I think what is most disheartening is how divergent the culture of the law enforcement community and the culture of the communities they serve* have become increasingly divergent. From my own perspective, it appears that law enforcement nationally is predominantly white and conservative, while the US population is growing more diverse and culturally more liberal. I believe this divide is really what exacerbates the tensions with police and communities we're seeing a lot of right now. They're fundamentally different cultures the power relationship between the two makes conditions ripe for conflict (its not inherent, just more likely). Perhaps that's why Austin, the "liberal" outpost of Texas sees this "surprising" degree of police conflict - the cultural chasm between the law enforcers and the citizens.
* Also depressing, when it seems more like law enforcement is terrorizing the communities within their jurisdiction rather than serving them.