Those who hold a negative view of humanity in general are very commonly bigoted against some group of people in particular. This is only natural. Because of course they want there to be some unchangible part of themselves which grants them special pardon from the universal gutter.
So those who regard human nature as generally evil will often declare this opinion to be realistic and self-evident, only the naive would disagree with them. Yet at the same time they will also declare that it is also common sensicaly obvious that their own people are inherently exempt from this evil nature. Race is the most famous claim to such immunity, though direct appeals to race have gotten more and more rare over the years. These days you are more likely to hear some pious claptrap about Judeo-Christian values, American exceptionalism, or 'The West'. The claim is that there is something innate within our culture that innoculates us from the bad parts of human nature. And since the vanity of such a claim is obvious, it is always buttressed with the insistance that believing such a thing is simply the minimum standard for loving your own people at all.
It is easy and trite to say of a stranger that 'he is as good as I', 'he ain't heavy, he's my brother' etc. But there is a reason why people would rather believe the asinine or frankly evil than embrace such seemingly easy dictates. It requires the strength to stare straight into the eyes of Stalin or bin Laden and say, 'Ok, since I have not murdered by the score I can be reasonably assured that I am better than him. But not by any natural essence, therefore only limitedly so and worse, not irreversibly so.' The ultimate truth here is that you had might as well give humanity the benefit of the doubt. It is the only honest way to give the same thing to yourself.