What did Donald Trump do today?

He demanded an apology from the cast of Hamilton, claiming that they had "harassed" Vice-President Elect Mike Pence.

A cast member read a brief statement after the curtain call asking for Pence to work on behalf of "the diverse America who are alarmed and anxious that your new administration will not protect us, our planet, our children, our parents, or defend us and uphold our inalienable rights."

So why is this so terrible?

• It is bad if a president-elect demands apologies for peaceful political speech he doesn't like. 

• The First Amendment protects free speech and in particular "the right of the people... to petition the Government for a redress of grievances."

• Presidents-elect who react this badly to brief, polite appeals will probably react much more badly to actual challenges when president.