Final answer:
The phrase pertains to a warning about the negative impact of political factions, as discussed by historical figures like George Washington who saw the potential harm they could cause to a nation's governance.
Step-by-step explanation:
The phrase "I have already intimated to you the danger of parties" signifies warned earlier about the hazards of political factions. This warning pertains to the potential divisiveness and the detrimental impact that organized political groups, or parties, can have on a nation's unity and effective governance. George Washington, among other historical figures, emphasized the importance of being wary of the mischiefs of political parties, expressing concern about how they could lead to partisanship overriding the common good.