A photo on a governor's old yearbook page surfaces showing a person in blackface and another wearing a white Ku Klux Klan hood.

The photo can't be written off as a "youthful indiscretion" because the people in it are adults.

The governor first apologizes for the photo then denies he's either of the people in the photo, while admitting he once darkened his face for a Michael Jackson dance contest.

What more do you need to know? The damage to Virginia Gov. Ralph Northam's credibility is so beyond repair that some critics say he has to go.

But here's an uncomfortable truth that photo won't reveal:

Some of the biggest champions for black people in America's past have been white politicians who were racists.

Some of our best friends were racist

A pop history quiz:

Who was the white Southerner who used the N-word almost like a "connoisseur" and routinely called a landmark civil rights law "the n----- bill."

That was President Lyndon Baines Johnson, the greatest civil rights champion of any modern-day president.

Who was the white judge who joined the KKK, marched in their parades and spoke at nearly 150 Klan meetings in his white-hooded uniform?

That was Supreme Court Justice Hugo Black, who incurred the wrath of his fellow Southerners when he voted to abolish Jim Crow segregation in the court's landmark Brown v. Board of Education decision.

And who was the white politician who also used the N-word freely , told racist jokes and said African-Americans were biologically inferior to whites?

That's Abraham Lincoln, the "Great Emancipator" and arguably the nation's greatest president.

The point of these examples is not to offer a historical loophole for any leader caught being blatantly racist. What happens to Northam is ultimately up to the people he serves and to his conscience.

But what I'm saying is that what matters to some black people -- not all, maybe not even most -- is not what a white politician did 30 years ago.

It's what he's doing for them today.

Who would pass the racist abstinence pledge?

I'm wary of those commentators who say they speak for an entire race of people. When a white friend sometimes asks what black people think of an issue, I sometimes tell them, "I don't know, I missed the Weekly Meeting for All Black People in America."

Yet I feel confident in saying this: Most are not shocked to hear that a white politician who is a purported ally is accused of doing something racist.

We expect racism from many white people. Even among liberals.

It's buried so deep that many white liberals don't see it, George Sachs said in a recent essay , "10 Ways White Liberals Perpetuate Racism."

"It's automatic and hidden. Binding and resistant to change," the psychologist wrote. "No matter how well-meaning we are, no matter how open-minded. Like the 'root kit' on a computer, racism is hidden and operating without our knowledge."

That's why we're sometimes able to accept a political leader caught being racist. And I'm not just talking an abstract acceptance of politicians from another era like Lincoln or Johnson.

I'm talking about contemporary politics.

President Bill Clinton once did something that infuriated so many blacks that some called it racist.

President Bill Clinton infuriated plenty of black people in 1992 with his "Sister Souljah" moment . The then-Arkansas governor was running for president when he compared the rapper Sister Souljah's angry comments about recent riots in Los Angeles to David Duke, a former grand wizard of the KKK.

But the black community still largely accepted Clinton because they didn't define him by that one remark. He was so beloved at one point that he was called the nation's first black president.

And then there's former Vice President Joe Biden.

Remember when he and Obama were competing for the Democratic nomination for the presidency in 2007? Biden called Obama "articulate and bright and clean," as if that was a rarity for a black leader.

But Obama went on to choose Biden as his running mate, and Biden is still so popular in the black community that he is considering another run for the presidency.

Even Obama learned to accept such flaws from a white person who was more than a political ally.

It was his white grandmother.

In the famous "race" speech he gave in 2008 when his candidacy was threatened by the release of his former pastor's angry condemnation of America, Obama invoked her.

"I can no more disown him than I can disown my white grandmother, a woman who helped raise me ... but a woman who once confessed her fear of black men who passed by her on the street, and who on more than one occasion has uttered racial or ethnic stereotypes that make me cringe."

If black people only worked with white allies free of any racism, bias or past mistakes, we would be alone.

Before the yearbook incident, Northam won the support of Virginia's black community. He forcefully denounced the 2017 white supremacist rally in Charlottesville that took the life of a young woman. He successfully pushed for the expansion of Obamacare in Virginia. Former President Barack Obama campaigned for him. He won almost 90% of the black vote in his successful run for governor in 2017.

That might help him, or it may not be enough.

What matters for some is not one act from a person's life but the entire play. Do they push for equality in the end?

What matters, too, is how they respond when they're caught in the act. Do they try to deny it, rationalize it with lines like, "That's not who I am today?" Or do they own up to their racism, make no excuses and vow to do better?

LBJ, the racist civil rights hero

President Lyndon Johnson is a prime example of someone who was able to rise above his racism.

In staff meetings, Johnson would routinely use the word "nigra" and "negra," according to the author Adam Serwer in an essay entitled, "Lyndon Johnson was a civil rights hero. But also a racist."

He shares a painful story from a biography on Johnson, when Johnson asked his chauffeur if he'd prefer to be called by his name instead of "boy" or the N-word.

When the chauffeur said he preferred to be called by his name, Johnson grew angry and told him, "No one's gonna call you by your goddamn name. ... So no matter what you are called, n-----, you just let it roll off your back like water, and you'll make it."

But Johnson was the same man who smashed Jim Crow by championing the landmark civil rights bill that formally ended American apartheid, Serwer notes.

President Lyndon Johnson was both a champion of civil rights and someone who displayed shocking racism.

Johnson's passion for civil rights was so heartfelt that the historian Doris Kearns Goodwin tells a remarkable story in a recent book. It took place when Johnson confronted a Southern senator who was leading the opposition against what would become the 1964 Civil Rights Act.

Sen. Richard Russell told Johnson that if he pushed the bill, he would lose the upcoming presidential election, and the Democratic Party would lose the South forever.

"Dick, you may be right. But if that's the price I've gotta pay, I'm going to gladly do it," Johnson says, according to Goodwin's book, "Leadership: In Turbulent Times."

No room for redemption

But could Johnson even survive as a leader today?

In the church of the modern-day media, there is no room for redemption. We have a zero-tolerance policy against anyone caught being a racist. They can apologize profusely without any denials or rationalizations, but they will most likely be banished from public life.

And no doubt this policy is good. We can't return to the days when politicians freely used the N-word in public. But I think we lose something when we don't allow any politicians to grow past their mistakes.

One of the reasons Johnson was such an effective champion for blacks is that he understood the Southern mind better than most. He was fighting against the same demons that he grappled with. He knew what buttons to push against the racist politicians who stood in his way.

Yet there is not much room for a politician to evolve in today's environment. There is a "rage industrial complex" that fixates on the latest racial flashpoint: an outrageous video, remark or image that's passed around social media like a viral grenade.

Meanwhile those banal acts of racism that don't get caught in a photo or a tweet go by unremarked.

Here's when I know there's genuine racial progress.

It's not when a white politician is caught being racist and people demand his or her head. It's when people show the same amount of public outrage over the everyday acts of racism -- voter suppression, racial profiling, redlining -- that define so much of our everyday lives.

Now that would be shocking.