Wrong, biden has excommunication himself by knowing the Church teaching and Publicly going against it and not repenting and admitting his Error Publicly. He is NOT Catholic, In Union with the Body of Christ, the Church. Yes it is This Simple.
Pray for his Soul for he is in Grave Error and Mortal Sin, If he dies in this State it will Not be Good for his Souls Eternity!
Don’t conflate the concepts of mortal sin and excommunication. Imprecision is never helpful in the long run.