According to Washington, what is the ultimate cause of political factionalism? Why does Washington believe that factionalism is most dangerous in "popular"- that is, republican-governments?

Answer and Explanation:

For Washington, the ultimate cause that promoted the existence of political factionalism was the existence of regional loyalties over national loyalty. By this Washington wanted to say that when government leaders are more interested in establishing benefits for themselves or just for the region they represent without taking into account the national benefit, they establish conflicts, discrepancies of opinion and political division, which ends up weakening the nation and it can result in cases of corruption, decadence and abuses of power.

He asserted that nations that adopted federalism were more likely to fall victim to political factionalism because they allowed each state to serve its own political interests, rather than forcing the entire country to serve a unique and national interest.