(CNN) The biggest tell to date of Joe Biden's 2020 plans came this week, when he apologized to Anita Hill.

"I wish I had been able to do more for Anita Hill," Biden told Teen Vogue in an interview . "I owe her an apology."

Hill, you will remember, worked for Supreme Court nominee Clarence Thomas when they were both at the Department of Education. During Thomas' 1991 confirmation hearings, Hill alleged that he had sexually harassed her. She came under withering criticism from the Republicans on the Judiciary Committee, which Biden chaired at the time.

Biden, as the years have passed, has been widely perceived as doing too little to defend Hill in that hearing. The optics of a committee of all white men questioning Hill, who is African-American, also aged poorly.

Amid the growing #metoo movement -- and the series of politicians who have either resigned or lost races while battling allegations of sexual harassment -- Biden's past with Hill was sure to grow as an issue in the coming weeks and months.

So he nipped it in the bud. For the second time in a month. (Last month, Biden was asked about the Thomas hearings and his role. "What I do feel badly about is the bad taste that got left in the mouth of some of the people around Anita Hill, and maybe even Anita, about whether or not the witnesses should have been called who were called and weren't called," he said.)

That is not an accident. Biden, a 75-year-old white man, understands how the treatment of Hill was perceived by many women and, in light of the cultural movement around women speaking out about harassment, he is working to clear up any sort of misunderstanding or hurt feelings around it. He is clearing the decks, purging his past of anything that could be seized on by, say, a future political opponent.

A future political opponent like, say, New York Sen. Kirsten Gillibrand, who has emerged as the leading voice of the #metoo movement on Capitol Hill. Gillibrand was the first senator to call for Sen. Al Franken's resignation in the wake of a series of allegations from women that he groped and forcibly kissed them. And she is very much looking at running for president in 2020.

"If I were offered the nomination by the Lord Almighty right now, today, I would say no because we're not ready, the family's not ready to do this. If, in a year from now, if we're ready, and nobody has moved in that I think can do it, then I may very well do it."

That's not a "no." Heck, it's not even a "maybe." It's basically a "yes ... probably." Biden's caveat -- "nobody has moved in that I think can do it" -- is the tell. He's a politician. Who was a senator at 30. A two-time presidential candidate. And a two-term vice president. Looking at that résumé, do you really think he is going to conclude that anyone who decides to run for the Democratic nomination in 2020 is really more qualified to do the job than he is?

None of that is to say that Biden is a lock for the race. He, more than almost anyone, knows the role that fate -- and unexpected events -- can play in a life, having lost his eldest son, Beau, to brain cancer in 2015

"I'm a great respecter of fate, but who knows what the situation is going to be in a year and a half?," Biden told the "Today" show last month. "I don't have any idea. I'm in good health now, I'm in good shape ... but I just don't know. Honest to God, that's the truth."

What Biden is doing right now -- with the Hill apology as the leading edge -- is not (yet) running for president, but preparing to decide to run for president.

To undertake such a gargantuan endeavor -- and, remember that Biden's two past presidential bids make him uniquely able to understand the challenges of a national campaign -- is something that requires years' worth of planning, plotting and thinking.

Think of it this way: Running for president is like an iceberg. The part that you see above the water is the time from the announcement of the bid to its end -- whether in victory or defeat. But that visible part is only a tiny fraction of the entirety of the actual iceberg that is floating below the surface. What Biden is doing right now is well under the water line -- checking for cracks, shoring up weak spots and the like.

If he runs, Biden almost certainly is the race's Democratic front-runner -- given his universal name recognition, his close relationship with Barack Obama (and the Obama political and money networks) and his personal story.

But a Biden candidacy doesn't clear the Democratic field. Not even close. With President Donald Trump's approval ratings already in the mid-to-low 30s, there will be a loooooong line of ambitious Democrats who see the party nomination as a near sure-thing into the White House.

And almost everyone in that 2020 Democratic race will be a fresher -- and younger -- face than Biden. What he cannot do is allow himself to be defined as a voice from the past before the race even begins. He knows that -- hence the Hill apology.

Make no mistake: Joe Biden is getting ready. And, given that, the expectation should be that he will run in 2020.