* A made-up phrase: Someone might have come up with it for a specific purpose, like a poem or a song.
* A misheard quote: Maybe it's a misremembered or mispronounced phrase from a piece of literature or dialogue.
* A metaphorical statement: It could be a way of saying something indirectly. To understand the meaning, we'd need more context.
Possible Interpretations:
* Rivers and bad governments are both flowing, changing things: Perhaps the phrase is drawing a parallel between the way rivers flow and the way bad governments operate. Both are in constant motion, sometimes unpredictably, and can cause damage and disruption.
* Light things "swim" on top: The "lightest things" could be referring to things that are superficial, unimportant, or easily manipulated. Bad governments might be seen as allowing these "light things" to rise to the top, while important issues sink.
To understand the meaning, you'll need more information. If you can provide some context – like where you heard the phrase or what the speaker was talking about – it might be possible to figure out what they meant.
