I was wrong about Kamala Harris. And that's a huge problem for Donald Trump.

Donald Trump has realized something that would have seemed impossible just a few years ago: A Black woman can beat him in a presidential election.

Trump’s decision to speak at the annual National Association of Black Journalists Convention and Career Fair in Chicago on Wednesday signals a recognition that he’s got to do something to turn down the heat that Kamala Harris has generated by taking over for Joe Biden at the top of the Democratic ticket .

Trump wouldn’t be making this play if he didn’t see Harris as a real threat, a development that has surprised me more than Trump’s rise in 2016 surprised the rest of the mainstream media.

I shouldn't have counted Kamala Harris out

From my vantage point as a Black man who has covered politics in one form or another for the last 20 years, I didn’t have any confidence that voters would give Harris a fair chance.

I’ve seen the struggles Black women have had in all areas of American society and figured the silent racism that creeps up in health care and employment would become deafening in a presidential election, giving Trump a clear path to the White House.

I’ve also heard whispers from Black voters who look at her ancestry, the daughter of a Jamaican American father and an Indian American mother, and question whether she’s truly connected to the African American experience enough to represent their interests.

And I remember hearing from older Black voters during Barack Obama’s rise, that they would vote against him to protect him. These voters had lived through the deaths of Medgar Evers, Malcolm X and Martin Luther King Jr. and were convinced that history would grimly repeat with a serious Black presidential contender.

What I didn’t factor was how organized and ready Black women were to support Harris.

A new Democratic ticket: Democratic voters want a radical ticket. It's not too late for Harris to give them one.

Harris' candidacy energized Black and white voters

For them, Harris’ experience at the historically Black Howard University and her membership in the Alpha Kappa Alpha Sorority, coupled with the reality that she has had to overcome all the same obstacles they’ve faced, more than proves her bona fides as a Black woman.

I also didn’t recognize how many Black men would step up to match the energy of their sisters in backing Harris.

And I certainly didn’t see how much that would charge up white liberals , eager to prove that their nation has moved beyond the stereotypes that have defined race relations since its founding.

I was being too pessimistic, too pragmatic, too skeptical and, frankly, too old school in my thinking and went so far as to say that Harris should bow out with Biden to make room for Sen. Mark Kelly of Arizona to take the Democratic nomination .

I can’t say this clearly or directly enough: I was wrong.

Harris is more than a viable contender. Harris can win this election.

Who will be Harris' VP pick? Kamala Harris doesn't scare Republicans, but Mark Kelly absolutely should

Trump sees Harris as a threat. Who would've guessed?

Ironically, it’s because of the support that I’ve been saying for years is the key to the White House: Excited Black voters create the margins needed for Democrats to win elections up and down any given ballot, and it’s especially true in presidential races as the most recent elections have proved.

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Harris has halted and reversed the momentum Trump gained with the one-two punch of his debate against Biden and the Republican National Convention.

And his move to accept an invitation to answer questions from Black journalists at the NABJ convention shows that he recognizes Harris as a real threat.

It’s something that would have seemed unimaginable just a few years ago.

Greg Moore is a columnist for the Arizona Republic, where this column originally published . Reach Moore at gmoore@azcentral.com or follow him on X, formerly Twitter: @SayingMoore

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This article originally appeared on Arizona Republic: I was wrong about Kamala Harris. And that's a huge problem for Donald Trump.