Billionaire businessman Michael Bloomberg officially entered the 2020 presidential race on Sunday, joining the large cohort of Democrats already competing to be the partys nominee in next years election.

We cannot afford four more years of President Trumps reckless and unethical actions. He represents an existential threat to our country and our values. If he wins another term in office, we may never recover from the damage, Bloomberg wrote in a message posted to his website . I believe my unique set of experiences in business, government, and philanthropy will enable me to win and lead.

Sundays announcement hardly came as a surprise. On Nov. 7, Bloombergs top adviser and multiple news outlets reported that the former New York City mayor was considering jumping into the race . The 77-year-old was expected to file paperwork to get on the ballot in Alabamas Democratic presidential primary, as the states deadline for candidates to formally enter its primary was Nov. 8.

Bloomberg also considered entering the race earlier this year, but said in March that it wouldnt make sense to run for president as a Democrat in the 2020 election when there was already a crowded field. He said he would instead back existing candidates who share his views, trusting former Vice President Joe Biden to carry the party as a moderate Democrat campaigning on bipartisan unity.

When reports came out that Bloomberg was again considering a run, his top adviser, Howard Wolfson, said it was because the media mogul is worried that the current field of candidates is not well positioned to defeat President Donald Trump.

If Mike runs he would offer a new choice to Democrats built on a unique record running Americas biggest city, building a business from scratch and taking on some of Americas toughest challenges as a high-impact philanthropist, Wolfson said Nov. 7. Based on his record of accomplishment, leadership and his ability to bring people together to drive change, Mike would be able to take the fight to Trump and win.

Bloomberg has been an outspoken critic of Trump since the 2016 presidential election, in January calling him a dangerous man who is recklessly running this country .

The businessman re-registered as a Democrat in October 2018, almost 20 years after he left the party and was elected mayor of New York City as a Republican in 2001. Bloomberg served three terms as mayor, the third time as an independent, and oversaw a city that erased its budget deficit and reduced its crime rate.

As mayor, Bloomberg also got heat for New York Citys growing homeless population, skyrocketing rent prices, his handling of the Occupy Wall Street protests and the controversial stop-and-frisk initiative by police, which disproportionately affected the citys people of color.

The billionaire has spent billions of dollars on social and political causes, including immigration reform and gun control. In 2006, Bloomberg founded the nonprofit Everytown for Gun Safety . He also donated more than $110 million to get Democrats elected during the 2018 midterm elections.

Bloomberg has touted his environmentalist credential, citing his new Beyond Carbon campaign , described as a grassroots effort to begin moving America as quickly as possible away from oil and gas and toward a 100 percent clean energy economy. But environmental groups like the Food & Water Action nonprofit feel differently.

This race doesnt need another candidate supporting tepid climate change policy, said Mitch Jones, Food & Water Actions climate and energy program director. As our climate crisis deepens, this is a which side are you on moment.

Bloomberg opposed efforts to ban fracking while serving as New York Citys mayor, according to Jones. He also said Bloomberg supported construction of the Keystone XL oil pipeline as well as continued use of fossil fuels.

It is clear that Bloombergs reputation as a climate warrior is drastically overblown, Jones said Nov. 7 after reports that Bloomberg was considering a presidential run. He has been and he remains a pro-fracking, pro-pipeline, pro-nuclear billionaire who favors half measures and false solutions because hes more interested in protecting his friends in the C Suite than he is in stopping climate change.

Bloombergs bid for the presidency makes him the richest person ever to run for the highest office, at a net worth of $52 billion . He joins fellow billionaire Tom Steyer in the field of primary candidates, though Steyers net worth pales in comparison at $1.6 billion.

Bloomberg made most of his fortune through Bloomberg LP, a media and financial information company he co-founded in the 1980s after leaving investment bank Salomon Brothers. The businessman has said that he would either sell the company or put it in a blind trust if he ever ran for president, to avoid any conflict of interest.

Regardless, Bloombergs status as a billionaire will surely stir the pot among the Democratic primary field especially from Sens. Elizabeth Warren (D-Mass.) and Bernie Sanders (I-Vt.), two front-runners who have built the foundations of their campaigns on overhauling wealth inequality and corporate power. One of Warrens biggest policy proposals is a wealth tax that would require ultra-rich people to pay an additional 2 cents for every dollar over $50 million in their personal fortunes. Sanders also proposed a version of the wealth tax and has made much of his campaign about the greed of millionaires and billionaires .