Former New York mayor Mike Bloomberg, one of the world’s richest people, announced his bid for the Democratic presidential nomination Sunday by promising to “rebuild America” and defeat President Trump.

The announcement, which Bloomberg telegraphed for weeks even after deciding earlier this year not to run, reflects his view that the current field of Democratic candidates is not well-positioned to win in 2020.

Bloomberg has promised a disruptive campaign that could break spending records with a massive advertising buy aimed at states that vote in March and April.

“I believe my unique set of experiences in business, government and philanthropy will enable me to win and lead,” Bloomberg said in a statement on his redesigned campaign website. “As a candidate, I’ll rally a broad and diverse coalition of Americans to win. And as president, I have the skills to fix what is broken in our great nation. And there is a lot broken.”

In an accompanying video, Bloomberg offered a preview of what he will focus on in the race, including his philanthropic work fighting gun violence, closing coal-fired power plants and funding medical research. Without offering specifics, the announcement video says he will push for the wealthy to pay more in taxes and to guarantee health care to all Americans without removing private insurance from anyone who wants it.

His campaign has made more than $30 million in television advertising reservations to help introduce him as a candidate. The ads will start Monday. He also has plans for what advisers call an “aggressive and robust digital strategy.”

Bloomberg has also announced a $100 million ad campaign to criticize Trump in key battleground states and a $15 million voter registration effort in those same places. Those initial spending plans are already double the amount raised by the top fundraiser in the Democratic field, Sen. Bernie Sanders (I-Vt.), through September.

Sanders, who has described his own campaign as a fight against the billionaire class, has been particularly critical of Bloomberg’s entry into the race.

“I’m disgusted by the idea that Michael Bloomberg or any other billionaire thinks they can circumvent the political process and spend tens of millions of dollars to buy our elections,” Sanders said Friday in a statement. “It’s just the latest example of a rigged political system that we are going to change when we’re in the White House.”

The initial Bloomberg ad campaign, in English and Spanish, will focus on his biography in an effort to introduce him to voters.

“Mike is not nearly as well-known to Democratic voters as some of the other contestants,” campaign adviser Howard Wolfson said. “When they learn of his unique set of accomplishments in business, government and philanthropy, they respond very positively. His story is compelling: middle-class kid who made good and did good.”

Wolfson said Bloomberg, who has a net worth of more than $50 billion, would release his tax returns over the course of the campaign, though he has not set a date to do so.

Bloomberg News editor in chief John Micklethwait sent a statement to employees Sunday announcing that the company had assigned a reporter to cover its owner’s campaign, and would disclose the relationship in stories. The company will also stop publishing unsigned editorials, which reflected the former mayor’s personal views.

“We are not going to follow an exhaustive rule book,” he wrote. “You prove you’re independence by what you write and broadcast, rather than proclaiming the ideas in advance.”

Bloomberg does not plan to raise any money for his race, though his campaign signaled an aggressive effort to attract volunteers and build an email list of supporters. His campaign will have an online store of campaign merchandise.

One of the first products is a T-shirt with one of his favorite aphorisms, “In God we trust. Everyone else bring data.”