Libs hate guns because they want a government monopoly on violence such that the populace cannot credibly resist. They care about this so much, because libs intend to force lots of extremely unpopular policies on people "for their own good" and know that an armed populace would fight back and thwart the lib agenda.

They fear that all their hard work over the last several generations to stage a complete takeover of government and an end to democracy would all be for nothing when the people ended up revolting anyway. They might even end up ousted from power through an armed rebellion and stuck with a right wing government occupying the totalitarian throne they spent generations making for themselves.