Passive income tax?

[Jacob Bell]

I was watching the CNN Debate tonight and I couldn't help but hear Hillary Clinton mentioning a tax on passive income and went on to say something about the need to tax all investment income? I don't know if she was specifically referring to the "rich" or all in general. Could anyone fill me in on what these policy plans might be and what kind of a result it might have? Also, correct me if I misunderstood what was said during the debate for those who might've watched.