Write to us at [email protected]. To subscribe, sign up here. Harvard University holds a unique place in American society. The school, 140 years older than the country it’s in, has educated more US presidents and produced more Nobel laureates than any other. When a fictional character is supposed to seem smart, like the lawyers in “Suits” or the protagonist of “The Da Vinci Code,” they go to Harvard. Yet as you’ve probably seen, Harvard has come under pressure in recent years. “The Harvard Plan,” an award-winning podcast from the Globe and WNYC’s “On The Media,” has been documenting those struggles....