A formal declaration of war brings all kinds of interesting legal issues to bear with respect to treason & sedition. For example, most/many people aren't aware that the 1917 espionage act - amended over the years - is still essentially in force.
An actual declaration of war would cease the interminable propaganda from the left that is aimed at defeating the will of the people to fight back in the first place. One only need reference WWII to see how opposition to the essential goal of actually winning a war is effectively eliminated.
We have to do something. We are getting picked off and killed.