Throw Someone Under the Bus

= cause someone else to suffer in order to save oneself or gain personal advantage

*This is a metaphorical expression.  We are not literally throwing someone under a bus.

Ex:  When the parents asked their sons who spilled the paint, one of the brothers “threw his other brother under the bus” by saying it was all his fault.

Ex:  The president made an embarrassing mistake, but instead of accepting the blame, “he threw the vice president under the bus” by blaming the mistake on him.