Why It Matters That Trump and Michael Cohen Had a Falling Out

Fixer. The title wasn’t a formal one, but Michael D. Cohen wholeheartedly embraced the role as a lawyer at the Trump Organization. It amounted to serving as chief problem solver for Donald J. Trump, offering Mr. Cohen an unusually up-close view of his boss’s personal and professional lives.

Mr. Cohen was often at Mr. Trump’s side in the decade before he became president, including helping him sort out difficulties leading up to the 2016 election. Most famously, he helped arrange hush money payments to two women — including the pornographic...