If the US president threatens to take away freedoms, are we no longer free?

Donald Trump's dramatic escalation in threats to deport or arrest citizens - from the world's richest person to Democratic lawmakers - should be taken seriously, experts say

Threats of retribution from Donald Trump are hardly a novelty, but even by his standards, the US president's warnings of wrathful vengeance in recent days have represented a dramatic escalation.

In the past week, Trump has threatened deportation, loss of US citizenship or arrest against, respectively, the world's richest person, the prospective future mayor of New York and Joe Biden's former homeland security secretary.