If “Long Story Short” told the story of the rise and fall of every empire, including our own, then Colin Quinn’s new one-man show, “Unconstitutional,” zeroes in on what makes the United States of America so unique and yet not quite immune itself to the perils of contemporary culture and decay.

It doesn’t matter if you’re a Republican or a Democrat. For you, as an American, the party is over. Quinn just happens to be the bartender and the counsel we need to hear at last call.

Quinn workshopped “Unconstitutional” over the winter at The Creek and The Cave, the Long Island City theater space and restaurant owned by Rebecca A. Trent, who directs Quinn in this production at the Barrow Street Theatre. If Jerry Seinfeld, director of “Long Story Short,” punched up Quinn’s stories to provide more jokes per minute, Trent’s direction here allows Quinn to find a more focused narrative.

The U.S. Constitution. Its very essence, and a continuing American philosophy, Quinn says, boils down to this: “Who died and made you king?” And he’s apt to rip something from the day’s headlines to prove it — in the case of a show earlier this month, he found truth in comedy in the recent arrest of Reese Witherspoon, who mounted an impromptu defense of her “rights” to police officers. That’s the Constitution for you. “It’s the document that the drunker you get, the more you understand it,” Quinn notes, adding: “It’s impressive that we talk about it, because nobody’s read the whole thing.”

So Quinn goes about taking us back to the Constitutional Convention and the writing of the document, and subsequent Bill of Rights, that Americans hold so dear and near to them in a clinch.

Turns out, if you do actually read the document that binds America, you can see the foreshadowing of our current financial and political crises. As Quinn walks up and down a series of steps to speak to us from multi-tiered soapboxes, a large screen to the left of the stage displays the U.S. Constitution’s preamble; and later, the First and Second Amendments in the Bill of Rights.

Here is that preamble, by the way:

We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.

How our founding fathers (and Quinn has his favorite) wrote independence as a way of dealing with daddy issues with England; how slavery and racial politics was written in there, too; how the separation of powers was an idea, like a drinking party, gone wrong. Some critics have jumped on a quote Quinn makes noting that President Barack Obama is the only one making jokes about the president these days, but Quinn himself has plenty to say about Obama, George W. Bush, Bill Clinton, Ronald Reagan, Harry Truman, Ulysses S. Grant and Andrew Jackson. Quinn also finds a way to show how your representative in Congress is in touch with your needs as much as Bruce Springsteen is, for better or worse, and pointedly proves that your vote does indeed matter.

Quinn laments how much we have neglected our true freedom of speech, instead using it only to complain, or in the case of contemporary cable news, to talk about the talk about the story instead of telling us what’s really going on.

If there only are two narratives — left-wing and right-wing — where does Quinn and everybody else fit into the discussion? As he jokes: “I’m pro-choice but I’m pro-gun. I’m pro-gay marriage but I’m also pro-death penalty. What do these things all have in common? I’m anti-overcrowding.”

He brings a discussion on freedom from religion directly to his temporary home near Ground Zero, notes that the Second Amendment is even more outdated when promoted by the NRA’s current policies, and relays amendments three through 10 as “street stories” that, when added up, are meant to give American citizens and the immigrants who come here a sense of hope.

All of which is embodied in one of the more disgusting displays of success in spite of itself we’re witnessing today via popular media and culture. “That’s what America is about. Don’t let shame get in the way!” Quinn boasts.

You’ll have to see Quinn’s show to hear him tell it to you straight.

But you’ll have to hurry before it really is last call at Quinn’s bar.

“Long Story Short” made the jump to Broadway and HBO, earning Quinn both Drama Desk and Emmy nominations. Will “Unconstitutional” do the same?

We can only hope. In Quinn we trust?

Colin Quinn’s Unconstitutional, at the Barrow Street Theatre.

UPDATED: Colin Quinn’s “Unconstitutional” will relaunch July 4! New run extends the show July 4-23 at Cherry Lane Theatre in NYC.