Unity requires some common foundational principles shared by all. The source of our current divide is a different set of foundational principles. One side reveres the ideals of the Declaration of Independence and the Constitution. It values individual liberty above all, within a reasonable framework of law and order. The other side reveres the ideals of Marx. They value the power of government as a tool to mold society, like it or not, into a predetermined ideal. These are not compatible visions. One of them is going to triumph over the other.
There is no unity to be had when one side says, "live and let live," and the other says, "conform, or else!" When your "free speech" becomes their "hate speech," your only choice is to conform, or fight. When your "right" becomes their "public menace," you must abdicate your right, or fight for it. When your attempt to persuade people subjects you to the violence of mobs and banishment form the public forums, being fired from your job, or expelled from your university, how do you unify with those who oppose you? You don't. You are in a confict which you will either win, or lose.