Both parties contributed to and maintained the status quo, because they both profit from it. Game theory works out and both try to balance their power roughly 5

Both parties contributed to and maintained the status quo, because they both profit from it. Game theory works out and both try to balance their power roughly 50/50 and keep everybody else out of the game. All topics are polarized to the extreme to fit into the 2 party divide. If a third party would emerge it would be slightly closer to one of the poles. Then it would immediately make that side lose even if more people voted for that position. That is because there is no percentage voting but a cascaded threshold voting. Thus, suppressing underdogs is in the interest of both. Abstract example: 44% vote party A for X 10% vote party B for X 46% vote party C against X 44% + 10% = 54% for X, but 46% is the biggest party so they win Question is why the Grand Old Party suddenly quit that century old cartel.