There was no hello. Just an angry voice on the other end of the line yelling obscenities about blacks and Latinos in North Philly. The man grew up there, he shouted, back when it used to be "a great white neighborhood." Then "the blacks" and "the Puerto Ricans" moved in and ruined it. They're garbage, he yelled. No, he seethed, garbage is better than them.

Oh, and before I or anyone else called him a bigot, he wanted me to know something.

He's no racist. His grandchildren are half-Puerto Rican.

My heart sank. Poor kids.

Remember the classic "I'm not racist. … I have black friends" argument?  Increasingly I'm finding more people trying to deploy the "I can't be racist. … My grandchildren/children are biracial" as a free pass to be as offensive as you please. Demographically, it makes sense. A recent Pew study found that the mixed-raced population in the United States is growing three times faster than the general population.

And when I say increasingly, I mean I had no lack of examples to choose from for this column. About a week ago, I listened to my cubicle-mate patiently field a call from a reader spewing a bunch of hateful comments, then saying his granddaughter is biracial so he couldn't possibly be racist.

Spoiler alert: Yeah, you can.

Family doesn't inoculate anyone against racism.

Tanya Hernandez, professor of law at Fordham University and author of a forthcoming book, Multiracials and Civil Rights: Mixed-Race Stories of Discrimination, said it fits into a larger societal idea that having closer relationships with people of other races can make people more empathetic.

It's a nice thought – especially after the post-racial fantasy we all fed on for the last eight years, and the ongoing myth that as the country's demographics become more diverse, racism will be eradicated. But the reality can be much more complicated, and painfully personal.

Consider the gut punch of an essay from Panama Jackson, who recently wrote about how President Trump's election has eroded Jackson's relationship with his white mother.

"Last week proved to me, pretty definitively, something that I feared but hoped wasn't true: Blood is absolutely NOT thicker than dangerous political and racial ideology," Jackson wrote. "Who you support, or don't, says everything about who you are as a person and what you think about the people around you."

Comedians may joke that Trump is America's first "racist grandpa" president, but he's certainly not the first racist grandpa, and having biracial relatives isn't necessarily making them less so.

"In their minds, they've already made a huge leap —  they didn't ostracize the white family member who is either in the interracial relationship or adopted a biracial child and gave them a biracial grandchild, whatever the dynamic may be," Hernandez said. "They feel, 'Look, I didn't cut anybody off, I haven't rejected this nonwhite child, it's not 1942, look how progressive I am that I'll call this person family.' "

How they treat that person is more telling, as is how they use their relationship to mask their own biases.

I heard a lot of these stories while working on this column, each more painful and personal than the last. I have plenty of my own. But the story Nicole Gonzalez Van Cleve shared is the kind that leaves a mark.

Van Cleve is a professor of criminal justice at Temple University and author of Crook County: Racism and Injustice in America's Largest Criminal Court. But years ago, she was working in the Chicago parks system when a coworker said Mexicans hose their kids down instead of giving them baths.

When Van Cleve told her to please stop saying that, that it wasn't true, and that it was enormously racist and offensive to her as a Mexican woman, the other woman only doubled down.

"She said, 'I absolutely will not [stop], and P.S., my daughter is half-Mexican, so I know these things.'"

Her relationship, Van Cleve added, "gave her a type of pass, an extra amount of privilege. A way to congratulate herself for supposedly being this post-racial woman that gave her a free pass to say these deplorable and harmful things and do so with impunity."

That's the thing with racism. It's a chameleon, forever changing its form depending on the environment.

But racism by any other name or relationship is still just that: racism.