We are sick of Republican presidential candidate Donald J. Trump about now.

His 11th-hour attempts to court “the blacks,” as he has referred to us on several occasions, show us what we already know — that he is both ignorant and racist.

That’s a dangerous combination. And it’s also why we have such persistent inequality in America — because racist bosses, corporate heads, school superintendents, police chiefs, policymakers and political wannabes including and like Mr. Trump are oblivious to their own racial biases. Ignorance and prejudice spring forth not only when they speak, but underpins many of the decisions they make that prove detrimental to African-Americans, Latinos, Asians, Muslims, Jews, women and on and on.

The latest examples from Mr. Trump:

Speaking Aug. 19 in Dimondale, Mich., to an overwhelmingly white crowd in the overwhelmingly white suburb of Lansing, he said he wanted the vote of every African-American in the country. “You live in poverty, your schools are no good, you have no jobs, 58 percent of your youth is unemployed. What the hell do you have to lose?”

He said illegal immigration disproportionately affects economic opportunities of African-Americans and Latinos.

Speaking Monday night to another almost exclusively white crowd in Akron, Ohio, he said, “It is a disaster” the way many African-Americans and Latinos are living. “Poverty. Rejection. Horrible education. No housing, no homes, no ownership. Crime at levels that nobody has seen. You can go to war zones in countries that we are fighting and it’s safer than living in some of our inner cities. ... We’ll get rid of the crime. You’ll be able to walk down the street without getting shot. Right now, you walk down the street, you get shot.”

He blamed “the failed policies” of the Democrats and promised that a Trump administration would “straighten it out,” bring back jobs and get rid of crime. Of course, true to Trump form, there were no details.

Aside from perhaps Omarosa Manigault of “The Apprentice” and Pastor Steve Parson of Richmond, it’s clear Mr. Trump doesn’t know many African-Americans and has had little meaningful contact with people of color. He refused invitations this summer to meet with members and to address the national NAACP and the National Urban League conventions. He also declined to speak to the joint convention of the National Association of Black Journalists and the National Association of Hispanic Journalists.

If he can’t even sit and talk with people of color about our concerns, or come into our neighborhoods and churches and meet and listen to people, how can he possibly think he has the solutions to address any of our issues?

We have listened to Mr. Trump and heard loud and clear his racist, sexist, anti-immigrant, anti-Muslim, xenophobic message.

He talks about us in largely white cities to largely white crowds. He’s the boss who’s afraid to talk to you, even look you in the eye, and yet unflinchingly will direct your life and your future as though he knows what’s better for you than you do.

We reject that. And we reject Mr. Trump.

Mr. Trump and his campaign are so disconnected from African-Americans that his own African-American campaign strategist in Florida, Sean P. Jackson, chairman of the Black Republican Caucus of Florida, was thrown out of a recent rally because he didn’t look like he belonged.

Is Mr. Trump really the best the Republican Party can come up with?

And we ask again: When will all right-minded Republicans stand up and repudiate Mr. Trump and his brand of ignorance and racism? When will the Republican Party dump Trump?