I don't think paul is an overt racist and I wouldn't even call him a secret racist, I don't think he is. But his ideas, proposals, ideology is based in racist ideas and racist sterotypes, he even quoted one to support his ideas!
I don't think that most conservatives are overt racists. Openly admitting to racism leaves you justifiably marginalized in public life. They're too smart to admit that openly. I don't even think most are secret racists because racism in this country brings with it the ideas of the KKK and slavery and segregation and such that I'm sure many decent conservatives wouldn't want to associate with.
The point is that the way the white people feel about minorities is a huge, if not biggest indicating factor for why someone is a conservative or progressive. Every white progressive I've ever spoken with has had a similar sentiment towards minorities in this country. Every white conservative I've ever spoken with has had similar sentiments towards minorities in this country. That's the biggest determining factor I see. The rhetoric and the reasons are the same as they've been for 200 years. People who instituted Jim Crow didn't admit to being racist either. For that fact, neither did many slave owners or pro-slavery people. Neither did many Nazis.
It's important to understand that practically every single racist argument made is defended and rationalized and explained away. The people who make these arguments, whether they're arguing that white people are evil or that inner cities have generations of people who don't value work, always attempt to explain that argument using some factoid or statistic or rationality.
All the rationality in the world is irrelevant, even if facts are correct. For example, if it was true that asian people get into more car accidents per capita than non asian people, it would still be racist to say "asians are bad drivers".
So while it may be true that people in the inner city have less employment per capita, it's still racist to say "inner city people are lazy and don't want to work" - it's racist because we know inner city as code for black and brown.