(CNN) On Sunday night, President Donald Trump went to the World Series in Washington. And got booed. Loudly. And even was subject to a "lock him up!" chant.

This was celebrated on Twitter. And by liberals nationwide. He got a taste of his own medicine! Now he knows how people really feel about him!

Which is, well, true. Trump very rarely appears in public at anything other than campaign rallies and official events. In both of those situations, he is lauded. There are just very few occasions -- except maybe, when his motorcade passes protesters -- where Trump comes face-to-face (or close) with people who really, really don't approve of how he is handling his job.

But what the booing and chants on Sunday proved isn't that lots of people don't like Trump. We already knew that. What it proved is just how much he has changed not just politics but public discourse more broadly -- moving the goalposts (or maybe knocking them down entirely) on what is acceptable behavior.

"I have a hard time with the idea of a crowd on a globally televised sporting event chanting 'lock him up' about our President," said Delaware Sen. Chris Coons (D) on CNN's "New Day" Monday morning. "I frankly think the office of the President deserves respect, even when the actions of our President at times don't."

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