Businessman and activist Tom Steyer remains in the Democratic presidential race and on the debate stage long after other party hopefuls exited the race. But why is he there?  What does he bring to the campaign that other Democrats do not?

In a conversation with Greg Corombos, Steyer explains what compelled him to run after initially deciding not to be a candidate.  They also dive into Steyer's signature issue of climate change.  What is his specific plan and is it realistic to think we can phase out fossil fuels entirely?

In Tuesday's debate, Steyer claimed his international business experience has prepared him to be commander-in-chief.  But how does that kind of experience specifically prepare him for deciding whether to commit U.S. troops to combat?

In recent weeks, Steyer has climbed to double digits in polls of voters in the early primary and caucus states of Nevada and South Carolina.  What's responsible for the surge?