so let’s break it down

execution is the killing part. it may be done by 3rd parties outside of the law (ie murder), or it could be the final part of a legal proceeding that leads to the death penalty

the death penalty is the conviction at the end of a legal proceeding

saying someone deserves the death penalty (ie jumping right to their conviction) skips the trial and sentencing etc of a normal legal proceeding. it’s not at all the same as saying someone should be tried for treason

he said that joe biden should be killed by the state no matter how you spin it