like the dog that caught the bus. To be in unexpected possession of something that one never expected to catch and that one has no sense of the purpose to which it could be put.

When I first read this simile, I imagined that the dog had waited for the bus the way that I do and managed to get on it. Silly me! I forgot that dogs instinctively chase moving things: sticks, tennis balls, animals, cars, etc., buses being among them. They do it simply because they must, not necessarily to any purpose. But what if a dog managed to get their teeth into a bus and bring it to ground? What would he then do with it? He has no idea except to hang on to it until...whenever, I guess.

This appears to be a political dog, though not exclusively. Christopher Caldwell quotes Republican strategist Ed Gillespie as saying, “We're like the dog that caught the bus.” Caldwell goes on to say that the Republicans are “clinging to power, even as they grow confused about what exactly they are supposed to do with it.” Maureen Dowd cites it as a favorite Washington expression.