fight a losing battle

bun fight

A debate or disagreement, usually with several parties involved, often political in nature.

fight fire with fire

To respond to an attack with a similar or identical counter-attack (e.g. to respond to gunfire with reciprocal gunfire).

fight fires

To deal with urgent matters and minor emergencies rather than longer-term work.

fight for one's life

To be in danger of dying (as a result of injury, illness etc.).

fight one's corner

To vigorously promote or defend one's interests, views, etc.

fight shy

To avoid meeting at a close distance or at close quarters; to keep out of reach, to avoid.

lose one's battle

To succumb to a serious illness.

not win for losing

To repeatedly fail in one's gambles or efforts.