The general rule in politics of English Canada is the smaller and further East a province is, 1) the less politics is divided on ideological lines 2) the more political patronage exists. PEI is the smallest province and one of the furthest East, and its politics have been the least ideological and arguably the most patronage based.

Clannishness is a symptom and cause of non-ideological politics. It's a truism that in democracy you are voting based on who you want to be in government, but really that and that alone has been the driver of voting behaviour in PEI. People are voting because they want specific people who they know personally to be in government, and those specific people have organized themselves into teams that have been working together for generations. I'm not just referring to elected officials and the relatively small number of explicitly political appointments, but government jobs in general. PEI has historically had an extremely high rate of civil service turnover even down to relatively low level jobs when a government changes.

There's also one additional factor that the political class in PEI went out of its way for generations to make sure was not a dividing factor in politics, which is religion. PEI has historically been evenly divided between Catholics and Protestants, and in order to make sure this didn't become a factor in politics, the districts were set up as two member districts, and each party would, by tradition, run one Catholic and one Protestant in each district, which would virtually ensure parity. This is in contrast to other provinces which have been divided along religious lines. Historically in Newfoundland Catholics had disproportionately supported Tories, whereas in Manitoba it was Protestants who had disproportionately supported Tories.