Michael Cohen and Rosie O’Donnell: A Love Story

The text came through on Michael D. Cohen’s iPhone on Monday morning, shortly before he took the stand in a Manhattan courtroom as the star witness in the criminal case against his former boss, Donald J. Trump: “breathe - relax - tell the truth - u got this - i love u.”

An hour later, another text came in from the same person: “Ur doing great.”

“Thank you and truly love you,” Mr. Cohen wrote back to the sender, who was not his wife, either of his children or another family member, but the comedian and actress Rosie O’Donnell.

Politics, the cliché goes, makes strange bedfellows. But few relationships seem as unlikely as the intense bond that has developed between Mr. Cohen and Ms. O’Donnell, two Long Island natives of the same generation who were pulled into Mr. Trump’s force field in vastly different ways years ago, and who connected as they surveyed the damage afterward.

It is not lost on Ms. O’Donnell, 62, that Mr. Cohen, 57, once helped carry out Mr. Trump’s campaign of insults against her, tormenting her for her looks and her weight and calling her “wacko.”

The story of their friendship is one of New York celebrity and Long Island aspirations, blustery personalities and oversize egos. It involves a prison visit, Barbara Walters, Twitter insults, forgiveness and a kind of shared world-weariness.

“We talk and communicate on a regular basis,” Ms. O’Donnell said in a long phone conversation on Monday. “I know this has been a tumultuous time, so I check in. It’s a big thing to be in a position to be able to change the whole country in some way.”