in the tank

prepositional phrase4

1. •
   (US) Supportive, approving, favorably disposed.

   • [J]ournalists were stung by a pair of "Saturday Night Live" skits that portrayed them as in the tank for Obama. — 2008
2. •
   (informal) In a state of decline, failure, or prolonged poor performance.
3. •
   In reserve; available for future use.
4. •
   (slang) Contemplating a decision for a long time.

   • He went in the tank after his opponent put him all in.