The announcement came after an underwhelming finish in the South Carolina primary and spending nearly $160M on his campaign. Tom Steyer, the California activist billionaire who has largely been a nonfactor in the Democratic primary campaign, dropped out of the race on Saturday night.

Steyer's departure came after a disappointing finish in the South Carolina Democratic primary. With 70 percent of the vote in, Steyer had just 11.5 percent of the vote — despite spending millions of dollars on campaigning there.

"There’s no question today that this campaign, we were disappointed with where we came out," Steyer told supporters in Columbia, S.C.

"But I said if I didn’t see a path to winning that I'd suspend my campaign, and honestly I can't see a path where I can win the presidency."

His exit came after he'd spent a total of $158 million on television and radio ads, according to Advertising Analytics. In South Carolina alone, Steyer had spent nearly $21 million as of Tuesday, the firm said.

Steyer had essentially put all of his efforts in recent weeks into South Carolina. He'd shown promise in recent polling in the Palmetto State and invested more time there than any of his competitors. His wife, Kat Taylor, even moved to Columbia earlier this month.