It is useless to hold a person to anything he says while he is in love, drunk, or running for office.

The line is a wry caution about taking certain kinds of speech as binding promises. MacLaine groups three states—romantic infatuation, intoxication, and political ambition—in which people are prone to exaggeration, self-dramatization, and strategic or impulsive claims. The humor comes from treating “running for office” as a kind of altered state comparable to being drunk or lovestruck. Beneath the joke is a skeptical view of sincerity: words spoken under strong emotion, impaired judgment, or public-performance pressure may reflect desire and image-management more than stable intention. The quote thus advises judging people by later actions and consistent behavior rather than by heightened, situational rhetoric.