Republican presidential nominee Donald Trump said on Thursday that the anti-Israel protesters who burned the American flag in Washington, D.C., on Wednesday should receive a one-year jail sentence.

Protesters burned the American flag waving in front of Union Station and hung up a Palestinian flag during Israeli Prime Minister Benjamin Netanyahu’s state visit to Congress on Wednesday. Trump said the burning was a “disgraceful display” that is being judged by powerful world leaders across the globe.

“Rarely have we seen anything like this. And I think you should get a one-year jail sentence if you do anything to desecrate the American flag. Now, people will say ‘oh, it’s unconstitutional.’ Those are stupid people, those are stupid people who say that,” Trump told “Fox & Friends.”