I assume suing Biden would not work because he is immune now and later will be either dead or 100% demented.
Biden is not immune... you ought to read the other posts in this thread. Biden called the kid a white supremacist and made other derogatory statements that put Rittenhouse in danger before he was elected. Nick Sandman who suffered a thousandth of what Rittenhouse did... reportedly got hundreds of millions of dollars. Suing Biden will be one more thing that will make Biden look like an oaf. Break out the popcorn... he is guilty as sin
POTUS is not immune from civil lawsuit. “It depends” (immunity) on whether the act is an official act. Kennedy was sued for car accident.
Paula Jones sued Bill Clinton for sexual harassment. POTUS said he was immune while he was POTUS - asked for a pause or stay in the case. SCOTUS ended up being the decider in Clinton v. Jones. Clinton lost the “delay” suit, and settled the harassment suit.
No need for Biden to be mentally fit to decide a defamation case. The words speak for themselves, and aren’t sarcasm or parody.