What the $?&(! is going on with our politicians?

The mayors of New York and Philadelphia and the governor of New Jersey let loose with a few choice vulgarities over the past two weeks in otherwise G-rated public settings, including a town-hall meeting and a City Hall event.

And all three men knew full well the microphone was on.

While foul language has been uttered in politics before, the blue streak is making some wonder whether it reflects the coarsening effects of pop culture in this reality-TV era of “Jersey Shore” and “The Real Housewives,” a decline in public discourse, a desire by politicians to come across as average Joes, or just a really hot summer.

First there was famously blunt New Jersey Gov. Chris Christie branding a lawmaker “one arrogant S.O.B.” at a town hall last month (and using some stronger epithets in discussing his passion for the music, though not the politics, of Bruce Springsteen in an interview published in The Atlantic this month.)

Then New York Mayor Michael Bloomberg, apparently having trouble stomaching a slew of puns in his prepared remarks for Tuesday’s contestant weigh-in at City Hall before the Fourth of July hot dog-eating contest, chuckled, “Who wrote this s—?” to guffaws from the crowd.

Then it was Philadelphia Mayor Michael Nutter’s turn on Thursday at a news conference at which he discussed a shooting a few blocks from the center of the city’s July Fourth celebration. He said he wasn’t going to let the city’s image be harmed by “some little ass—- 16-year-old.”

“My sense is: Because they want to appear to be in tune with popular culture, politicians feel free to express themselves in profane ways,” said Rutgers University political scientist Ross K. Baker. And he finds that troubling: “I honestly do believe that, in aping the coarseness of popular culture, people in public life are really dragging us into a discourse of fang and claw.”

President Harry S. Truman was criticized for his use of such salty language — for his time — as “hell” and “damn.” And many Americans were shocked by Richard Nixon’s liberal use of profanities on the Watergate tapes, which made “expletive deleted” a pop-culture catchphrase.

In more recent years, then-candidate George W. Bush was caught on what he didn’t realize was a live microphone describing a reporter as a “major-league ass—-,” and Vice President Dick Cheney hurled the F-word at Vermont Sen. Patrick Leahy on the Senate floor.

In 2010, Vice President Joe Biden was heard using the F-word on live television in a whispered congratulation to President Barack Obama at the signing of his health care bill.

The seeming proliferation of political swearing reflects changes in both social norms and the media landscape, said Robert Thompson, director of the Bleier Center for Television and Popular Culture at Syracuse University. Offhand remarks that might once not have been reported now get captured on video and posted online.

“Politics has been nasty” for years, Thompson said. “The difference is we now have media that show this stuff.”

Nutter, who has used vulgarities before in response to street violence, has described his language as an “honest, clear, direct response.”

Christie has built his political career on his brash style. His warning to people to “get the hell off the beach” as Hurricane Irene approached last year appeared in big front-page headlines around the state.

As for the lawmaker who was the target of the Republican governor’s salty remark last month, he’s not complaining.

“He actually gave me national attention,” Democratic state Sen. Paul Sarlo said. “The term is more of an insult to my mom, who is not politically involved.”

Still, Sarlo saw the comment as unbecoming of a governor who has been mentioned as a possible vice presidential contender.

The biggest problem with political figures using bad language is that it crowds out whatever they were actually trying to say, said etiquette expert Lizzie Post of the Emily Post Institute. “The words we’re focusing on are probably not the ones they want us to,” she said.

And what of the average citizens politicians are trying to reach — or, perhaps, emulate?

Kristina Klimovich, for one, doesn’t like to hear them swear. “I think there’s always a line, and as a public servant there are certain standards they have to adhere to,” said Klimovich, of New York.

But Lisa Garfield of Springfield, Mass., said, “It makes them more human.”

“I’m 52 years old,” she said, “and I don’t know anyone who’s never used a cuss word in their life.”