President Obama (re)learned a political lesson as old as time on Monday night: Don’t mess with the Boston Red Sox in Massachusetts. Like, ever.

The president was reportedly booed at a fundraiser in Boston after making reference to a trade this week between his hometown Chicago White Sox and the BoSox.

“Finally Boston, I just want to say: Thank you for Youkilis,” Obama said, referring to longtime Red Sox third baseman Kevin Youkilis, who was traded to the White Sox on Sunday.

It didn’t go over well with the crowd. Reporters in the room said Obama was booed, as did the White House transcript and Obama himself.

“I didn’t think I’d get any boos out of here,” Obama said. ”I should not have brought up baseball. I understand. My mistake. My mistake. You gotta know your crowd.”

On Tuesday, however, the White House said that the boos were really just attendees cheering “Youk,” as they often do at games when Youkilis bats.

“Anyone who was in that room last night knows that the preponderance of people shouting in response to what the president said about Kevin Youkilis were saying ‘Yook’ and not ‘Boo,’ for God’s sake,” said White House press secretary Jay Carney, himself a Red Sox fan.

(All of which reminds us of a great moment in “Simpsons” history in which Mr. Burns asks if people are booing him or yelling “Boo-urns”.)

Regardless of what actually happened, it’s clear the president failed to learn the lessons of many Massachusetts politicians before him.

It was just two years ago that Democratic Massachusetts Senate candidate Martha Coakley joked that former Red Sox pitcher Curt Schilling was a Yankees fan and balked at the idea that she would shake hands outside Fenway Park in the cold. Anybody who tries to tell you those things didn’t factor into her special election loss doesn’t know the primacy that the Sox hold in then minds of Massachusetts voters.

Similarly, Sen. Scott Brown (R-Mass.) has gotten some heat for saying in an ad that he loved Fenway since he advocated for it to be moved a decade ago. And opponent Elizabeth Warren, at a debate, couldn’t name the two years last decade that the team won the World Series.

Before them, Sen. John Kerry (D-Mass.) got some bad press for mangling the names of Red Sox players Manny Ramirez and David Ortiz, and saying Eddie Yost was his favorite Red Sox player, despite Yost never having played for the team.

Despite those cautionary tales, Obama stuck his foot in the fire. And he got burned — just check the headlines coming out of the event.

“President Obama Makes Kevin Youkilis Joke To Red Sox Fans, Who Respond Like Red Sox Fans,” read one.

“The Last Remaining Third Rail in US Politics: The Boston Red Sox,” read another.

The moral of the story is that, when it comes to a passionate fan base, it’s best not to poke the bear in any way, shape or form. People don’t have a sense of humor about their sports teams — especially in cities like Boston, New York and Philadelphia. (Note to those making jokes about field hockey to The Fix: Just. Don’t. Do. It.) Those teams are a way of life for many people in those communities, and longtime players like Youkilis are almost like extended family to many of them.

(Maybe we should forgive Obama for not having such a connection to his team; after all, his White Sox have won only one World Series title over the last 95 years and regularly lose their division to a much classier organization, the Minnesota Twins.)

Obama is not going to lose Massachusetts because of this — or even a real Northeastern swing state like New Hampshire, for that matter. Even the boos were reported to be light-hearted, and almost certainly were.

But this may be the last time we see Obama mention baseball on the campaign trail.‎