President Obama spoke Wednesday to Al Sharpton’s National Action Network’s 20th Annual Keepers of the Dream Awards gathering in New York.

Obama addressed an increasingly critical fact of American life — that the price of a gallon of gasoline is pushing $4. (In Chicago, where I live, and where Obama still keeps a house, even “regular” has topped the $4 mark.) The president knows that the unemployment rate might creep down toward 8 percent and make his reelection likely, but rising gas prices can trump all that and make him a one-termer.

So President Obama told his audience, "I don’t pump gas now, but I remember what it was like pumping gas.”

Well, that was fuel for Limbaugh’s Thursday morning radio rant.

The talk show host treated the remark as if he had caught the president in a lie — Obama claims to have worked in a gas station filling the tanks of customers. If that was so, Limbaugh asked — noting that the only menial job Obama has described was as an ice cream scooper —  why has no one ever come forward with memories of working the gas pumps with the future president?

And so Limbaugh ended up revealing more about himself than about the president. Does Limbaugh know that “self-serve” has been a part of American life for decades?

Yes, Rush, even U.S. senators and Illinois state senators, and University of Chicago Law School lecturers, and community organizers, and maybe even candidates driving through the Iowa cornfields during the early presidential primary season, pump their own gas.

So now we know that either Rush wastes money at the “full service” pumps, or, more likely, his retinue of drivers and assistants fills his tank — or tanks. Later in the broadcast, Limbaugh described his “fleet” of automobiles.