Well not only that, but it's also like saying that an officer using force should be acceptable. It's true, but it doesn't mean that it's the only way to handle a situation, and often, claims of racism and bigotry are used to end an argument as if it were an argument itself. I'm not saying that "the left always does that", but each side had their share of desperate ad hominem attacks, and racism accusations is one often used by those on the left (though on the right it's used, just either reworded, or subtly redefined).