Frank Monaldo I recently enjoyed a high school soccer game between two rivals. The game began with a spontaneous respectful set of handshakes. Though the game ended calmly enough, there were periods of frustration and tension that resulted in shouting and pushing matches. Despite this intense competition, the players intuitively understood how much they relied on the exertions of the other team. They could only develop and excel because of the unrelenting competition and effort of their adversaries.
Political parties share much of the same traits of sports teams that compete.
There exist real and important issues in contention, but part of politics involves the joy of competition. Political competition brings bracing disciplines. Political corruption and abuse of power are more common in political jurisdictions where one political party dominates, effectively unchallenged. Strong competitive parities have a cleansing effect. As Americans, we enjoy two strong national parties with long histories.