Former New York City Mayor Michael Bloomberg is charting an unorthodox path to the White House. Bucking decades of political ritual, Bloomberg skipped formally participating in the first four contests of the Democratic primary and staked his ground on bringing in a big delegate haul on Super Tuesday.

Progressive critics, such as Senators Elizabeth Warren and Bernie Sanders, derided Bloomberg for using his personal fortune — estimated to be worth more than $60 billion — to purchase a large number of television, radio and digital ads. In response, his supporters have repeatedly said his experience and wealth are both assets in defeating President Donald Trump.

“Our real goal here is to make a change in the White House, and you’re going to need somebody who can go one-on-one with Donald Trump, and I think Michael Bloomberg is the only one in the field that can do that,” Ed Davis, the former commissioner of the Boston Police Department and the head of Bloomberg’s Massachusetts campaign said during an interview with Boston Public Radio on Tuesday. “He’s a tenacious, tough, smart individual who knows Trump intimately.”