They put their political arms around him, and by extension President Barack Obama’s arms, and they talked about children being killed on Chicago’s streets, the latest murder caught on video and broadcast around the world on YouTube.

If you’ve spent any time in a big American city, you’ve seen this liturgy before, a sad scene, expected and politically necessary, televised, a liturgy repeated for several generations now.

By their speeches, the politicians transform a murder victim into a political icon, the dead now oblivious yet quite utilitarian, a fulcrum for government funding and calls to action.

The Obama administration may not be much for governing and tough decision-making, but when it comes to symbolism and aiding the mayor of Chicago, it is quite adept. Last week it was Daley’s failed push for the 2016 Olympics. This week it’s the murders.

“This is not a show-and-tell,” Daley said, when a reporter wondered whether Wednesday’s public relations effort was more dog-and-pony-show than real policy.

“This is not just words written in speeches,” Daley insisted, jaw fixed, teeth jutting forward behind his lips. “This is a commitment.”

I believe the mayor is sincere in this. You can’t blame him for teenagers who swing broken railroad ties against another teenager’s skull. Though I’ve criticized him for treating the Chicago area as his kingdom, I have no doubt he truly feels deep and helpless pain when such deaths occur.

Daley is the mayor. Daley is not the father. He didn’t raise the kids who commit the crimes. He didn’t fail to instill respect for life in those who swing the clubs or pull the triggers. You can’t blame him for the bad and indifferent parenting of others.

But he’s also a politician in trouble, with sagging approval ratings and little money to spend on programs that could really help, especially after he dropped hundreds of millions of dollars on insider deals for his pals. The cops don’t have a contract. He feels the pinch, and he needs to be seen as doing something.

And so the Obamaites arrived, Attorney General Eric Holder and Daley’s former schools chief and Obama’s basketball buddy Arne Duncan, now secretary of education. Each had a part. You’ve seen this sort of thing before.

The politicians cry out against the violence yet warn against blaming indifferent parents for raising malevolent barbarians. Community leaders reach for the government cash for those anti-violence programs that they say, this time, will finally solve things.

Everyone delivered their lines, flawlessly, earnestly. The only one who didn’t was dead.

Once, the name of the victim-as-icon belonged to Dantrell Davis, a 7-year-old killed in 1992 while walking to school near the Cabrini-Green housing development. More recently, there was Starkesia Reed, a 14-year-old honors student shot inside her Englewood home as she looked out a window in 2006.

There have been others. There will be more. But Wednesday’s name belonged to Derrion Albert, 16, fatally beaten near Fenger High School, his body crumpling while Obama and the mayor focused on Daley’s Olympic dreams.

There have been dozens of other Chicago public school students killed in recent years. The difference was that Albert’s death was caught on video. There was no video for Dantrell, no video for Reed.

“Nearly two weeks ago, this nation was shocked, shocked by a video showing scenes of such graphic violence that they’ve left an indelible mark in the mind of every American who has seen them,” Holder said. “For me and for this administration, it was a call to action.”

They talked on and on, offering familiar slogans. They would get to the root of the violence. The status quo is unacceptable. If you think you’ve heard it before, you have.

While they were speaking, I was standing on a dry patch of 111th Street, where Albert fell during a brawl, his head crushed.

“A staff member pulled him in from outside, and he lay on the floor right where you’re standing,” said Linda Cotton at the Agape Community Center. “He was unconscious and bleeding, he was gasping for breath.”

She didn’t see Albert fall. What caught her eye, though, was another teenager standing in the midst of the fight, taking a video.

“I was focusing on the person taking the video,” she said. “I couldn’t believe that someone would do that, take a video like that.”

I believe it. So do the politicians. That horrific video seen worldwide is why the president sent his men to the West Wing, at LaSalle and Randolph streets.

The ancient urban political liturgy transforming the dead into useful icons now has a new beginning. It begins with YouTube.

But I’m not giving up. It still is a great idea, the president of the United States and the Department of Education asking schoolchildren to write letters about how they can help. Yes they can!

If the White House changes its mind before the president’s back-to-school broadcast next week, then I’m ready. We could call it “Let’s Help the President,” or how about “Rat Out Your Parents!” Even better, let’s label it:

“Hey Kids, Don’t Ask. Just Tell.”

To help out, I’ve come up with 10 topics for Obama to discuss with the kids.

No. 1: “Hi, kids. It’s me, President Obama. I’ve got kids, too. And a dog. Aren’t dogs great?”

No. 2: “Have your parents ever said the words ‘offshore account’? If so, don’t ask them what that means. Just write down in your notebooks how many times they say ‘offshore account’ and then write me a letter. Remember, children: Don’t ask. Just tell.”

No. 3: “Do your parents watch Fox News on TV? Or are they unselfish Americans who care about the environment and what’s fair and watch MSNBC?”

Under the original idea, students were to prepare for the president’s broadcast by writing letters to themselves about how they could “help the president.” Then they’d discuss it with their teachers, and presumably later with their parents.

If you have kids, you know that at school the next day, they’d tell their teachers everything their parents said. Everything.

Predictably, the angry right-wingers complained Obama was trying to “indoctrinate” the children. But with the president’s poll numbers dropping and his nationalized health care policy tanking, he couldn’t afford being branded an indoctrinator.

So the federales backed off. Now the kids will write letters listing their own “educational goals,” as if they’re being subjected to their annual human resources salary review in some bleak future. How sad.

Only a few weeks ago, the White House was asking adults to write in any time they heard a neighbor or friend say something unkind about the president’s national health care plan. If it was OK for adults to inform on their neighbors, why can’t kids inform on their parents? Isn’t this America?

Here are some more themes Obama could discuss, if he changes his mind about the letter-writing business and takes the important extra step of having the kids send the letters to his Ministry of Information:

No. 4: “Is your mom or dad a doctor? If so, have you ever had a carpenter come over to your house, and the carpenter makes cabinets, and your parents say, ‘Let’s barter.’ Do you know what ‘Let’s barter’ means? Don’t ask. Don’t tell them. Just tell me.”

No. 5: “Do your parents subscribe to National Review or The American Conservative or The Weekly Standard?”

No. 6: “If you have braces and your dad is an electrician or your mom, say, is a plumber, do they ever complain about having to ‘do stuff’ for the orthodontist on Sundays? Like if you get new braces and the orthodontist doesn’t send your parents a ‘bill,’ what’s that about? You can tell me. Don’t you just hate braces anyway?”

No. 7: “Do your parents ever say they’re going to a ‘Tea Party?’ ”

No. 8: “Do they ever read Republican National Committee pamphlets before going to a town hall meeting about my health care plan?”

No. 9: “Are your parents bitter? Do your parents have guns? Do they cling to those guns as they cling to their religion?”

No. 10: “Do your parents own a business, and do they ever say, ‘It’s great to have a cash business,’ and ‘Isn’t this a nice new car?’ How many times have they said such things? Don’t ask. Just tell.”

Thanks kids,

President Obama.

Naturally, the partisan teeth-gnashing would be reversed if a Republican president addressed school kids, asking for “help” in fighting a “war on terror.” Democrats would argue the children’s minds were being cynically poisoned by the military-industrial complex. And they’d be right.

When I was in grade school during the Vietnam War, one of our teachers — a young man of draft age — informed us that communism wasn’t that bad, especially for impoverished villagers. So I went home to discuss it with my dad, who grew up an impoverished villager in Europe and fought in a bloody civil war against communism.

Dad, I said, communism isn’t that bad. It just helps the villagers. My teacher said.

He didn’t speak. But he had three cigarettes going at once, then started grabbing slices of bread off the table, mashing them in his palm, muttering something in Greek that is unprintable.

And the next day, I told the teacher everything.