It is more than that. It is an open declaration of war because the liberals plan for Federalization (Turning the Republic into a Federal State) has been set back. He is pushing FEDERALISM, starting with Abortion ‘Rights’ and against State Rights. They want to destroy the Republican Constitution and replace it with an Authoritative pseudo democracy with Central Authority. So the what he was crying about is Central Authority vs. State Authority, which essentially he was crying that the “Maga” Republicans want to rule themselves. The Civil War was not fought over Slavery, which is what is taught, but it was fought over State Rights versus Federalism. So in effect, what Biden is doing is declaring war on States Rights.
My read on history suggests that the South's positions on slavery and states rights were intertwined. I would argue that if there were no slaves in America, there would not have been a Civil War. One of the main contentions of S. Carolina and its impetus to secede was that Northern states did not uphold the Fugitive Slave Act. So again, I believe that in 1860, slavery and states rights were intertwined and absent slavery, there would not have been a Civil War - IMHO.