It’s not just Sheldon Silver on trial in Manhattan federal court: It’s the whole system.

Silver’s defense is that corruption is the bread and butter of New York politics — so how can it be a crime?

The prosecution says Silver, for decades the state’s second-most-powerful official, “picked the people’s pocket to line his own.”

To which Silver’s team answers, So what?

“It’s impossible, absolutely impossible,” argued defense lawyer Steven Molo, “for a member of the Assembly to . . . do the job that a person in the Assembly does and not have some sort of conflict of interest.

“That may make you uncomfortable,” he added, “but that is the system New York has chosen, and it is not a crime.”

Uh-uh. New Yorkers never intended it to work like that. (If they had, why did Silver keep his lucrative dealings secret?) But it’s clear the system does work that way — and then some.

Heck, Molo basically agreed with prosecutor Carrie Cohen’s contention that Silver used “You scratch my back, I’ll scratch yours” deals to line his pockets to the tune of $5 million.

“They” — meaning the prosecution — “don’t like the fact that friends might do favors for friends,” explained Silver’s lawyer.

That, Molo claims, is “conduct which is normal, conduct which allows government to function consistent with the way that our founding fathers of the state of New York wanted it to function.”

(Didn’t know the founders wanted that? Well, who are you to argue with Shelly? His district includes the Statue of Liberty!)

Just a wink and a handshake — that’s how “the people’s business” is supposed to be done? No way. What Team Silver calls normal government is a culture of corruption — one that’s poisoned Albany for decades.

How corrupt is it? On Tuesday, Dr. Robert Taub testified he referred 25 patients ailing from asbestos exposure to Silver’s law firm in return for state funding Silver arranged for his research center. Silver then pocketed huge fees (on top of a six-figure salary) from the firm.

Prosecutor Cohen says, “This was not politics as usual. This was bribes and kickbacks, illegal criminal conduct.”

The jury will decide if it was a crime. But it sure looks like bribes and kickbacks — and Albany politics-as-usual.