Some actions which excite a heated discussion, like painting a face, or dressing a certain way, have nothing to do with racism, but a lot with juvenile stupidity.
As I already mentioned, I would really like to know when and why this word has become the N-word in its current usage.
Slavery is bad, awful, inhumane. However, the human race has a very long history of slavery. Many wars ended up by bring slaves to the country of victors. Vikings were using slaves in their villages. For centuries Russia had a cast of slaves. Slaves, and then serfs existed in Russia until 1861 - almost the same year when ... you know. Those slaves were not brought from other countries, they were Russians. But their owners could do, and did, to the slaves whatever they wanted to do, even bad, awful, inhumane things. Everyone who thinks that African Americans were the only people suffering from slavery is simply wrong.
Slavery was (and somewhere still is) the most inhumane form of exploiting humans by other humans. However, even slavery has been removed from many societies, there are still other - less visible - forms of exploitation. Any event when one person uses another person as a tool for his/her individual purpose is a form of exploitation.
From the general point of view, there are only two forms of human interaction: exploitation of one person by another person; or collaboration between different persons. It's either - or. So, when choosing what politician to support, ask yourself, does this guy want to exploit you, or he/she wants to collaborate with you? And what would you do it the guy would be exploiting other people but no you? And judge by the actions, not by the words, because people who want to exploit others always lie. Always.