The 52-year-old New York Democrat made the announcement Tuesday on "The Late Show with Stephen Colbert."
Senator Kamala Harris outlined her vision for a unified America and also criticized President Donald Trump's border wall while promoting her new book in New York City.
The California businessman was one of the top donors during the 2018 congressional midterm elections. Steyer spent $120 million in support of Democratic causes last year and helped more than a dozen candidates make inroads into Congress.
The New York Democrat has gotten a mixed reaction on Wall Street, with some being hesitant to back her in what will likely be a protracted and expensive Democratic primary.
The commitment to shut down the fund comes after Warren told MSNBC's Rachel Maddow on Wednesday that she believes candidates running for the party's nomination should avoid funding their campaigns through PACs.
Steyer is part of a large list of potential candidates for the Democratic Party's nomination in 2020. The tour could be a make-or-break stretch for his presidential ambitions.
Democratic megadonor Bernard Schwartz says he's had private dinners and meetings with House Speaker-designate Nancy Pelosi, Senate Minority Leader Chuck Schumer and other party officials to propose a unified economic policy platform for 2020.
If the former New York City mayor contributes that much to his own campaign, he will have one of the largest 2020 war chests and a stark advantage over the other Democratic presidential nominee hopefuls.
Sanders lost the 2016 South Carolina primary by a large margin, and allies have said he would need to bolster his operations there if he wants to win this time around.
Former HUD Secretary Julián Castro to meet with donors on Wednesday as he looks to put together a formidable donor war chest ahead of a potential 2020 run for president.
Sacca's plans come during a seismic shift in how political movements and causes are funded and organized, largely through online entities.
"Deepfakes" began with celebrities' faces getting inserted into porn videos. Now the nascent phenomenon could be a threat to democracy, according to experts.
Former Vice President Joe Biden spoke at the University of Montana last night and gave the clearest signal yet that he's a 2020 presidential candidate.
But Joe Biden says his family "needs to decide as a unit whether we're ready" for him to run for president in 2020.
These early conversations with top-tier consultants in Iowa, where the major parties hold their first contests of the presidential election season, are the latest signs Booker could be preparing to launch a campaign.
It's a sign that Republican Party insiders are taking the prospect of a Bloomberg run seriously as President Donald Trump prepares to run for re-election.
Richard Ojeda and others who declared early candidacies will have a lot of trouble breaking out of what's expected to be a large field consisting of several Democrats, potentially including Sen. Elizabeth Warren and former Vice President Joe Biden.
Sayoc's alleged targets included Barack Obama, Hillary Clinton, Joe Biden and billionaire Democratic donor George Soros.
Earlier Monday, a new suspicious package was discovered at CNN's facility in Atlanta. That news network previously received two pipe bombs that Sayoc allegedly sent.
"There is great anger in our Country caused in part by inaccurate, and even fraudulent, reporting of the news," Trump says in a new tweet.
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