The scarcity mentality always ends up eating the host philosophy because it operates on a more fundamental level of the psyche.
All of this would be survivable if the mentality was going away in a few years. But it is not going away. The underlying conditions of scarcity are only going to get worse. Moreover, the warrior mentality builds on itself. As the right pulverizes the left, the left feels the need to pulverize back, and on and on. This is a generational challenge. Trump will be succeeded by some other warrior.
Eventually, conservatives will realize: If we want to preserve conservatism, we can’t be in the same party as the clan warriors. Liberals will realize: If we want to preserve liberalism, we can’t be in the same party as the clan warriors.
Eventually, those who cherish the democratic way of life will realize they have to make a much more radical break than any they ever imagined. When this realization dawns the realignment begins. Even with all the structural barriers, we could end up with a European-style multiparty system.
The scarcity mentality is eventually incompatible with the philosophies that have come down through the centuries. Decent liberals and conservatives will eventually decide they need to break from it structurally. They will realize it’s time to start something new.