to sway or flicker with the breeze

To bend with the wind; used to describe someone who lacks their own principles or opinions and simply follows whichever side is more powerful or influential.

To change course according to the wind direction

(idiom) a person who lacks strong convictions and easily changes their opinions or loyalties to suit the situation; literally a willow that bends with the wind

(idiom) to adopt a different attitude depending on the circumstances; to follow the wind; to go with the flow in a pragmatic or opportunistic way