WATCH: Trump supporters viciously boo protesters for holding up copies of the Constitution at rally

Donald Trump booted a baby out of a rally earlier this week, so it's not so surprising that he'd boot out people waving copies of the Constitution at his rally.

During a rally in Maine on Thursday, several protesters stood up and held out pocket copies of the United States Constitution. Even though they were standing and holding Constitutions, they were not chanting or vocally interrupting Trump's speech.

They were quickly escorted out of the room by security while being booed by Trump supporters.

The protesters' decision to hold up copies of the Constitution is a clear nod to Khizr Khan, the Gold Star father whose son Humayun died in Iraq in 2004. Khan, who is a Muslim, pulled out a copy of the Constitution during a speech at the Democratic National Convention last month in which he challenged Trump to read it.

Check out the video of Constitution-waving protesters being ejected from a Trump rally below.