OK, so Hume tends to use the word faction to stand for what we’d call party or lobby group. His view fits nicely with contemporary intra-political party issues, and with concerns about the members of the political class. Even so, he highlights the tension between tribal loyalty and passionate policy:
When men act in a faction, they are apt, without shame or remorse, to neglect all the ties of honour and morality in order to serve their party; and yet, when a faction is formed upon a point of right or principle, there is no occasion when men discover a greater obstinacy and a more determined sense of justice and equity.
Essays, Moral and Political (1741). Essay II Of The First Principles of Government