What's the deal with public figures becoming politicians?

The rumour mill is spinning out of control that Oprah will run for presidency in 2020. 

So what does she have in common with the likes of Tamati Coffey and Maggie Barry? They are all public figures who have run for public office. 

It seems to be an increasing trend but is it a good idea? Associate professor of politics Jennifer Curtin spoke to Duncan Garner about the year that was. 

Watch the video.