John Hinderaker at Powerline sums it up well:
I am guessing that these billboards were paid for, overwhelmingly, with taxpayer money; i.e, yours and mine. A considerable amount of that money, if you trace it back, was no doubt borrowed from Asian banks and governments. So, consider this: Chinese peasants are saving their money so that their banks can lend many billions of dollars to the Obama administration, which in turn passes some of those dollars on to universities and other non-profits so that they can spend millions to erect billboards accusing white Americans of being racists. Is this a great country, or what?
Still a great country in spite of the efforts by the left to make it less so.