It would definitely require a change in mentality, here in Denmark we have 14 parties in what is equivalent to congress and senate. There is a total of 179 representatives and the smallest parties have a single member, while the largest have 42 and 48 respectively.Yeah, people try to get rid of parties, but it just doesn't work.
Preferential voting allows more parties, though in Australia we've still only got 2 really viable options (Labor and the Liberal/National coalition), with the Greens way below either of them.
But, as you might note, 48 is still pretty far from the 90 votes you'll need to pass anything. That way coalition building becomes a requirement, the parties are forced to interact and negotiate with each other.
That's what I'd want for the US, instead of this all or nothing BS.