He does not.
I mean, the evidence is in a case like this. Set aside the accuracy of this claim, the superlative he wants to claim here here just does not exist at all; there is no "least racist person." Extremes of racism could perhaps be measured in some way: how many negative things you say or do to people of how many races. But the negative extreme can not be quantified. How would you establish that one minimally racist person was even less racist than some legitimate contender?
So the fact that he applies to himself superlatives that are nonsense shows that he just can't think or speak in any other terms.
The problem is that people figured out a long time ago that Trump is easily manipulated simply by complimenting him. The better and bigger the compliment sounds, the more he does what you want. He probably speaks this way in part because people have been saying things like this about him for a long-ass time. But he's utterly oblivious to the fact that they just say things like that to get him to do what they want. They're utterly meaningless manipulations that his ego wouldn't allow for him to just ignore, or cast aside.
Someone, I think perhaps a Trump biographer, made a really interesting point about him, which is that what he calls "awesome dealmaking" is really just making normal deals which may or may not be to his advantage on paper, and then welching on them while relying on the other party's assumption of good faith to have them hold up their end of the bargain. He never actually learned how to make a deal, he learned how to use people's better nature against them to get what he wanted. Sign a contract, other party starts performing, then you withhold payment and "renegotiate" basically by holding them hostage - either they take a drastically reduced payment or they get no payment at all. If they complain, then they get sued.
The problem he is having is that nobody in Washington negotiates in good faith to make a deal, they're all basically doing what he's done his whole life - which is to negotiate something, and then act pursuant to the negotiation in whatever way is in their own best interest. He doesn't seem to understand that the people he is negotiating with don't lose anything if he pulls the rug out - they can walk away unscathed and tell him to go frak himself and then blab to the media about the racist stuff he said.
I think he fully expected for Dick Durbin to show up to the WH, Trump would then renege on the immigration deal, and then Durbin would simply "renegotiate" and sign onto whatever hardline agreement he and Tom Cotton and John Kelly had come up with. What Trump still doesn't seem to realize is that people aren't going to "renegotiate" simply because he wants them to, or because he's going to tweet about them if they don't. And I don't know that he'll ever really understand that he's in a different reality than he's used to. I don't think he has the intelligence to adapt.