I know quite a few LEO's personally. Most are actually pretty bright, and know both their coworkers and targets well. The overwhelming thought is that LAW enforcement in the US can hold down pretty much any uprising as long as they can keep control of the narrative, and make sure that average folks don't identify with the folks being beaten/hosed/shot. You can see this in action if you look as news commentary of OWS, or the G8 protests. Crazy Kids. You can see it in action if you mention collateral damage of drug and/or GWOT raids to CSD. An article was written about it by a LEO (That I can't currently find) where he SAYS the key is to make sure the news reports that the raid target is a wacko. To this day most Americans think Randy Weaver was a nazi criminal and deserved it.
They might be betting incorrectly. Or they might not have as firm a grip on spin as they have in the past, but you'd be foolish to think LEA's don't consider this very thing.
ETA: And they are currently incorporating the new data from Cliven's BLM thing. That lesson was lost on no one. Next time, no taking of cows. Quick raid, whole family grabbed, and new release about whatever evil crime you can find.
Dismissing dissents as crazy, bad or "not one of us" is not a new tactic. Probably was popular during the Roman or Greek empires.
It's honestly impressive folks respond to the hippy protests. Cops show up in the thousands with armored vehicles, (hopefully) less lethal weapons and mass detention. Folks barely blink. On the other hand, RKBA rallies tend to get a couple. Usually for traffic control. Last one I attended had extra officers emergency dispatched... to keep people from stepping on azaleas. No kidding, I asked him. "Hey, I see more officers than usual, what's up? - People have been walking on the flower beds because the main stairs are blocked. We just landscaped, so we don't want it messed up."
If the hippies wanted not to get beaten up, they'd get a bunch of their hippy buddies, buy AR15s, take a couple classes, and open carry on their hippy protests. Combine that with a bit of personal hygiene and some common sense, guaranteed that they won't get night sticked, pepper sprayed and mass ziptied. Actually engage in oh, organized lobbying, voting campaigns and PR campaigns, maybe they'd get something done.
Most cops are normal people. Mostly 'good', but obviously self-interested. They're not going to go out of their way to be difficult, especially when folks are well organized, reasonably polite and whatnot. They will however do as they're told, because they often have kids and a mortgage. That tends to inhibit folks' moral compasses, especially if they can rationalization it.