Question

Pull the Rug Out from Under You to unexpectedly withdraw support; to suddenly place somebody at a disadvantage; to ruin someone's plans, hopes, or dreams

Accepted Answer

I asked Marcus to be my campaign manager, but he decided to support someone else and pulled the rug right out from under me. An American writer in the middle of the 20th century imagined a person standing on a rug, and then, all of a sudden, the rug pulled right out from under him or her. The person would be hurt or at a disadvantage lying on the floor. The writer applied that image to destroying someone's expectations or activities.

Idiom	Pull the Rug Out from Under You
Example	I asked Marcus to be my campaign manager, but he decided to support someone else and pulled the rug right out from under me.
Meaning	to unexpectedly withdraw support; to suddenly place somebody at a disadvantage; to ruin someone's plans, hopes, or dreams
Origin	An American writer in the middle of the 20th century imagined a person standing on a rug, and then, all of a sudden, the rug pulled right out from under him or her. The person would be hurt or at a disadvantage lying on the floor. The writer applied that image to destroying someone's expectations or activities.

Rug Pulled Someone's Writer Person Pull I Asked