Why does the king laugh when he asks Gulliver if he's a whig or a troy?

In Jonathan Swift's "Gulliver's Travels," the king laughs when he queries Gulliver about his political affiliations as a Whig or a Tory because he finds the concept of such partisan divisions amusingly trivial in the context of his own society. The king's laughter highlights the absurdity of human politics and reveals his perspective that these conflicts are petty compared to the more significant issues facing humanity. It underscores Swift's satire of political factions and the often ridiculous nature of political discourse.