“There are only two grades to get,” goes the ancient snark, “A or F. Anything else, it’s as if you aren’t really trying.”

As I wind up the semester at Barnard this week, I’m thinking about my students’ final grades: What those grades mean, and what they tell us — or fail to tell us — about a young person’s future. Most of my students are going to do well in the classes they took with me, as well they should; they worked hard.

But it’s hard to know whether good grades predict success.

Donald Trump, of course, spent part of the 2016 campaign criticizing Barack Obama for being a terrible student, wondering aloud why the man had been admitted to Columbia and Harvard. He demanded — climbing upon his high pony — that Mr. Obama release his transcripts. Mr. Obama didn’t.

Then, last February, we learned that Mr. Trump’s former attack dog, Michael Cohen, had written letters to the Wharton School at Penn and to the College Board, threatening legal action if they released the president’s college transcripts or his SATs. You know, like if they did the exact same thing Mr. Trump had demanded of Mr. Obama.