Presidential hopeful Tom Steyer can buy attention. Will that turn into votes?

Tom Steyer speaking at the 2019 California Democratic Party State Convention at the George R. Moscone Convention Center in San Francisco, California. Credit: Gage Skidmore (CC BY-SA 2.0). 

California billionaire and presidential candidate Tom Steyer be on the debate stage on Tuesday because of unusually high poll numbers. His polling jumped in two key early primary states last week. A Fox News poll showed him at 15% in South Carolina, which puts him second (only behind Joe Biden). In Nevada, he tied for third with Elizabeth Warren at 12%. 

Also, New Jersey Senator Cory Booker withdrew from the presidential race this morning. What went wrong?