As a candidate, President Trump passionately denounced the way minorities in inner cities are forced to attend substandard public schools, deal with high crime and be denied good job opportunities. He promised to make it a priority to fix that. So he met with the Congressional Black Caucus in March, and he just extended an invitation to the entire CBC to meet with him again at the White House. And they rejected the invitation.
The CBC is reportedly angry that Trump hasn’t acted on their policy requests from March yet (odd, since there’s certainly been nothing to distract him from getting important work done in the past few months), and they’re afraid he might use the meeting for a photo op to boost his standing with black voters.
It seems to me that if they really cared about helping the people who sent them to Congress, they’d go find out what the President wants to talk to them about. I highly doubt that he invited them to meet with him just to boost his standing with black voters, but the CBC’s refusal even to accept the invitation should definitely lower their standing with black voters.