It started with just a few American retirees. These days, two dozen players fill the courts at the municipal sports center most mornings, swinging paddles at plastic balls. There are so many clubs in Mexico dedicated to the U.S. sport that a tournament was held here last year.
"It was a madhouse," said Victor Guzmán, a 67-year-old entrepreneur from Charlotte who helped pull the event together.
President Donald Trump regularly assails the flow of migrants crossing the Mexican border into the United States. Less noticed has been the surge of people heading in the opposite direction.
Mexico's statistics institute estimated this month that the U.S.-born population in this country has reached 799,000 — a roughly fourfold increase since 1990. And that is probably an undercount. The U.S. Embassy in Mexico City estimates the real number at 1.5 million or more.