Barack Obama: “It would make the country less secure at home, and reduce our ability to protect the Nation’s borders.”

A drift towards extremism was "not inevitable

I think when we act on that basis, it doesn't always work out, but over time things do get better.

And I will fight for that, even if I don’t always think it’s going to win.

If I had a blame pie for why politics is so polarised and why we're seeing a rise of populism in many places, it's because of that information that is going into our brains every day.