[rickydroll]

Here is a better article that I intended to post, plus a couple more for some nuance on 1a protected speech vs. regulated speech

https://nefac.org/is-heckling-a-speaker-a-crime/

https://www.aclumich.org/en/cases/hecklers-veto

https://stanfordmag.org/contents/the-first-amendment-does-no....

[Volundr]

None of these establish heckling as illegal. The first two are about the police not being able to arrest the target of the heckling for incitement (which, yeah, clear 1st amendment violation), the last is about Stanford imposing limits, which is entirely different from the government doing so.