Tom Steyer, the former hedge-fund executive and progressive activist, announced his candidacy for the 2020 Democratic presidential nomination on Tuesday, joining a crowded field.

“If you think that there is something absolutely critical, try as hard as you can and let the chips fall as they may. And that is exactly what I’m doing,” Steyer, 62, said in video declaring his bid.

In his announcement video, Steyer focused heavily on corporate greed and its undue influence on politicians in Washington. He stressed that big business’s avarice is the root cause of major issues such as climate change and the U.S. opioid crisis.

“Almost every single major intractable problem, at the back of it, you see a big money interest for whom stopping progress, stopping justice is really important to their bottom line,” he said.

Steyer made his fortune as the head of an investment firm and is worth roughly $1.6 billion, according to Forbes. He and his wife, Kathryn Taylor, are signatories to the Giving Pledge, a coalition of ultra-wealthy individuals that have promised to give away at least half of their wealth to charitable causes.

“We relish the opportunity to do our part and leave our collective campsite cleaner and better tended than we found it,” the couple wrote in their pledge.

In recent years, Steyer has championed several progessive causes, most notably combating the climate crisis, and has been heavily involved in California politics. He launched the liberal advocacy group NextGen Climate in 2013, which was later renamed to NextGen America following the election of President Trump.

Steyer has also been a leading voice in the impeachment movement against Trump. In 2017, he founded Need to Impeach, which lobbies members of Congress and has since gained over 8.2 million supporters.

“Through the important work of NextGen America and Need to Impeach, which I will continue to support, I've focused on registering & turning out the youth vote, and pressuring Congress to hold this president accountable by beginning impeachment proceedings,” Steyer added on Twitter. “But it's not enough.”

Tuesday’s announcement is a reversal for Steyer. He told The New York Times in January that was would not run for the White House and instead focus on doing “whatever it takes” to remove Trump from office.

Steyer’s entry into the crowded field comes just a day after California Rep. Eric Swalwell became the first candidate to bow out.