Sen. Bernie Sanders became the most famous socialist in America — and then he became a millionaire.

On Tuesday, the New York Times reported that after a long pressure campaign, Sanders has agreed to release the past 10 years of tax returns, and they will reveal that the man who built a political career railing against capitalism has joined the ranks of the top 1%.

“I wrote a best-selling book,” Sanders told the newspaper. “If you write a best-selling book, you can be a millionaire, too.”

A week after the 2016 election, Sanders released the book Our Revolution, a mix of campaign memoir and political manifesto. It became a New York Times bestseller.

Sanders began his campaign trailing Hillary Clinton by over 60 points in polls, but his socialist outsider message appealed to younger voters, liberals, and those who wanted to challenge the system, and he made it into a real race.

Ironically, his long harangues against the rich, by making him into a national celebrity, in turn enabled him to build a successful brand and cash in.