Both political extremes (the left and right) are driven by outrage and disregard for rules. In this sense, we have a commonality.
Similarly, both sides believe in individualism as sacrosanct while confoundingly enshrining only a particular version of individual rights. Once again, a commonality.
But, perhaps the commonality underlying these similarities is the largely emotional, self-serving, and unethical desire to win at any cost: winning is the justification for any behavior, and law-fare or individual rights are merely the most useful tools.