Francis Fukuyama in Persuasion:
Many people have recognized the centrality of polarization and offered solutions for how to get out of it. Among these are: institutional changes, especially to our electoral laws, that would restructure the incentives under which politicians operate; the growth of a third, centrist party that grabs the middle ground from the extreme wings of the existing two; and grassroots movements to build moderation and understanding from the bottom up. All of these will be important components of depolarization, but none of them will be sufficient by themselves or take place soon enough to solve the problem.
The path out of polarization needs to be a political one, given the nature of our democratic system: that is, a realigning election in which one party decisively wins control of both houses of Congress and the presidency and holds on to power through two or three electoral cycles. These realignments are rare, but in conjunction with the other pathways suggested may be in reach in the coming years if one of the two parties plays its cards right.