Nobody is saying that. Blacks are just as capable as whites, or Asians, or anyone else, of making those kinds of decisions and thoughts. However, it is true that during the last election, blacks (as a voting demographic) largely voted for Obama, and indications are that the overriding reason was racial solidarity. That is simply how it happened. What is says is debatable, but I don't believe that anyone argues that is implies that blacks cannot think of grander concepts. Myself, I think it simply says that, as a group, they voted alike. Nothing more, nothing less.
Blacks in prior presidential elections to the last one had been voting at about 90% democratic.With Obama on the ticket that may have been up a couple % points.They would have voted for Hillary at over 90% as well or any other democrate.The republicans have no one to blame for the very low support they enjoy among minorities but themselves.They adopted a policy of racial wedge issues in the 60s to attract a larger white vote and that worked to win them several elections.Republicans realize this and have made some attempts to be more inclusive by such things as naming Steele as the head of the RNC,but they are still being held hostage by their evangelical aging white right wing base who really has no interest in being a big tent even if that is political suicide.