"the process of polarization is not symmetrical. The parties have not become equally ideologically..."

“the process of polarization is not symmetrical. The parties have not become equally ideologically homogenous or moved equally far toward their extremes. They do not behave in the same way or share the same attitude toward established social and political norms. Republicans have moved farther right than Democrats have left.”

- The left’s gone left but the right’s gone nuts: Asymmetrical polarization in action | Grist