Not that far past the age of 21, I can remember back to the good ol’ days, seven weeks ago, when it was a racist sin to criticize a black politician.

Overnight, from Jan. 19 to Jan, 20, the law was flipped – by President Obama during his final hour in office. He made it mandatory to rip on every black politician – as long as he was Republican.

While the latest liberal girls’ march yesterday for who-knows-what was clotting the traffic for serious persons, Frankie (I Hate Research) Bruni, who is gay, slavishly was bowing to his master.

Mr. Bruni is known for seeking to destroy any critic of gay guys or the gay lifestyle in his New York Times essays. This time he dipped deeply into his bucket of boos to humiliate the brilliant neurosurgeon Dr. Ben Carson, black Republican.

Mr. Bruni, who is quite white, made fun of Dr. Carson because he is black. This is a disgusting stunt only liberals are permitted/encouraged to pull because liberals run the world, dictate the morals and certify the exact language we may and may not use – or risk being smeared as a societal outcast.

If you are a liberal, you not only may but should call any black man or woman a dirty name — as long as your target is Republican.

The peril embedded in this No. 1 Rule of Liberal Conduct is that liberals are entirely emotional characters. They don’t research. They don’t verify their own claims. They just go off the reservation. Every day. Undisciplined, they regularly explode – like a fellow loaded with pot and booze.

Activating his full lexicon, Mr. Bruni devoted all 21 paragraphs of his bullying essay to insulting Dr. Carson, the new Secretary of Housing and Urban Development.

Dr. Carson ignited the Bruni ire of limpid literary lore by calling the African slaves immigrants.

Addresing a HUD audience, Dr. Carson said:

“There were other immigrants who were brought here in the bottom of slave ships, worked even longer, even harder, for less. But they, too, had a dream that one day their sons, daughters, grandsons, granddaughters, great-grandsons, great-granddaughters, might pursue prosperity and happiness in this land.”

On cue, the liberal dog-and-pony show began. Oh, my, the phonies were exorcised.

Did you hear what Carson said? the easily offended liberal chorus roared.

Then a brilliant libertarian site, www.thefederalist.com, discovered – cough, cough – that America’s last racist president, B. Obama, laid out the identical case on at least 11 occasions.

Ooops. Now what, boys?

He Who Must Not Be Criticized, employing language similar to Dr. Carson’s, said in those 11 speeches that it was fair to call slaves immigrants.

Not one liberal bleat was heard. The boys were frozen.

Dr. Carson merely was echoing He Who Must Be Obeyed.

Isn’t that applause-worthy?

The 11 citations underscore how many times the unoriginal Mr. Obama gave the same speech – a topic for a separate day.