First is their issues and they are certainly free to have whatever positions they want despite the fact that theirs are untenable and destructive.
Second is the manner in which they defend their position and this is what is problematic. Maybe it is because their positions are untenable that they need to stoop to such dirty tactics or maybe it is because their leadership is using Alinsky's or Marx's rule of ends justifying means.
But whatever it is, their strategy of impugning their opposition with all manner of lies is their Achilles Heel IMO.
Their policies don't work and that alone will lead to their failure. But more importantly, their vile, demonic nature, inclined to lies and character assignation, makes them repellent to all but the most ardent Leftist voters.