Having lived for some time under a parliamentary system of government with 4-5 major political parties, I can tell you that it promotes highly dysfunctional and ineffective governance and is likely to be disastrous here in the U.S.
Ah yes, the good ole ‘90s when Canada had “Pizza Parliaments”. Jean Chretien’s Liberals won enough seats in Ontario and the Maritimes and a handful elsewhere to form a government, but the West had Reform/Canadian Alliance, Quebec the Bloc Quebecois, and the Maritimes had a few federal (Red Tory) PC and also NDP seats. And the talking people in 1997 thought it was dangerous for the Reform Party to become Her Majesty’s Loyal Opposition instead of the separatist Bloc.