Republican Senator Marco Rubio is tipped to be chosen as Donald Trump's Secretary of State. If he's given the role, the 53-year-old from Florida will be the first Latino Secretary of State in US history. In the past, the two have been critical of each other, but in recent years, Mr Rubio has been a strong supporter of Mr Trump. David Smith, Associate Professor at the US Studies Centre spoke to the ABC's PM program about the news.