I looked it up and I’m guilty of believing the propaganda on this one.

What he actually said was, "I do, however, believe that corporations which deliberately, purposefully, maliciously and systematically sponsor climate lies should be given the death penalty,"

Here’s the link: https://www.foxbusiness.com/politics/flashback-robert-f-kennedy-jr-once-called-for-koch-industries-and-exxonmobil-to-be-put-to-corporate-death.amp

He clarified that he believes in the first amendment, just not for corporations. My apologies.