Democratic presidential candidate and former Vice President Joe Biden addresses the Rainbow PUSH Coalition convention late last month.

Until last week, we thought the 2020 presidential election would be a battle of the septuagenarians — Donald Trump vs. Joe Biden.

Now, not because of what U.S. Sen. Kamala Harris, D-California, said but because of what the former vice president didn't say, we're not so sure that will come about.

Anything can happen between now and November 2020, so we're not about to predict a win or a loss for any candidate in the general election. But we believe Biden missed his moment in the recent first round of Democratic debates.

Harris was ready; the Delaware career politician was not. That was telling.

The kerfuffle came up because Biden in days before the debate had bragged about getting things done while in the Senate. So confident was he in his ability to get things done that he said he even was able to work with segregationist Sens. James Eastland of Mississippi and Herman Talmadge of Georgia.

"At least there was civility," he said. "We got things done."

Eastland and Talmadge were Democrats, same as Biden. That little fact has been mentioned in few, if any, of the sagas.

His idea, a sound one, was to compare people with different viewpoints working together for the good of the country to today, when Democrats and Republicans don't seem to be able to work together on almost anything.

Cut to the debates.

Harris, who many reports say had planned to confront Biden, the polling leader for the nomination, began her soliloquy by telling him, "I do not believe you are a racist, and I agree with you when you commit yourself to the importance of finding common ground. But... "

She went on to say "it was hurtful" to hear him talk "about the reputations of two United States senators who built their reputation and career on the segregation of race in this country." She then went on to talk about his opposition to busing, which was only a partial truth.

But that was Biden's moment. In a second, he could have answered Harris with what should have been righteous indignation, saying he would never apologize for working together for the good of the country.

He could passionately have explained his personal feelings on race, and cited whatever he believes were the positive efforts and votes he had taken to bring people together. And then, turning to her, he might've explained that while he abhorred the segregationist senators' views, he would never apologize for working with them to pass legislation for all of the American people.

Had Biden been feeling his oats, he might've calmly added that, frankly, he resented Harris's backhanded way of implying he was a racist, and he didn't need to be lectured by a one-term senator on how to get things done in Washington, D.C.

Despite the recent awkward allegations against him about being too much of a toucher and close talker with women, he would have been the subject of all the spin-room discussion after the debates instead of her. Trump Democrats might've have sat up in their chairs and said, "Yeah, that's our Joe. He isn't too old. He hasn't lost it, after all."

Instead, in his retort to Harris, he attempted to litigate busing, threw in Dr. Martin Luther King Jr. and former President Obama, and wound up seemingly glad he could stop talking, saying " anyway my time is up."

He may be right. The Joe Biden Train may have jumped off the track permanently.

But he made it worse over this past weekend, apologizing if he "somehow gave the impression that I was praising those men who I successfully opposed time and again. Yes, I was [wrong]. I regret it. And I'm sorry for any of the pain or misconception it may have caused anybody."

That's not the tough Joe Biden Pennsylvania coal miners supported. That's not the fiesty Joe Biden union workers counted on. That's the new Joe Biden who's now woke on political correctness, who's now down with all the kids who want to open the borders and give illegal immigrants free health care.

That candidate is likely to become the Jeb Bush of the 2016 Republican campaign, the George H.W. Bush in the 1988 Republican primary trying to avoid "the wimp factor" (before it turned out he would face Michael Dukakis, the little man in the tank, in the general election).

Mr. and Mrs. Middle America don't like everything about Trump, but they want somebody in opposition they can rally around, someone who speaks their language. Biden may once have been that man, but he'll have a hard time doing that now that he's missed his defining moment.