Five years ago, I warned about the risk of a Donald J. Trump presidency. Most people laughed. They thought it inconceivable.
I was not particularly prescient; I come from Italy, and I had already seen this movie, starring Silvio Berlusconi, who led the Italian government as prime minister for a total of nine years between 1994 and 2011. I knew how it could unfold.
Now that Mr. Trump has been elected president, the Berlusconi parallel could offer an important lesson in how to avoid transforming a razor-thin victory into a two-decade affair. If you think presidential term limits and Mr. Trump’s age could save the country from that fate, think again. His tenure could easily turn into a Trump dynasty.