It seems to me you believe in what some call post-modern liberalism as opposed to classical liberalism. There are now no limitations on the growth of federal power to bureaucratize all economic spheres in American life.
Voting is only one part of opposition. It is perfectly legitimate to sabotage the political agenda of one's opponents.
There is no limit on the vision of the American left. There is nothing the left cannot impose on people who are classical liberals.
America is now based on separate identity politics. The Democratic Party is primarily a party of non-whites and very well heeled and educated whites. The Republican Party is primarily the party of non-elite whites. Do you see how the attempt by one side to impose its will on the other side in the era of a shrinking/slow growing economic pie will have explosive consequences for American social cohesion? America is going to become a much more deeply divided country in which grievances are held by all groups.