turn (someone/something) against (someone/something)

to cause someone or something to oppose someone or something else.

He took all of our proposals and turned them against us.

Advisors have been trying to turn the president against increased military spending.

• be a weight off your mind
• be a weight off your shoulders
• be a writer in the making
• be backed into a corner
• be back in harness
• be back on the rails
• be backward in coming forward
• be bad news
• be bag
• be banging head against a brick wall
• be banging your head against a brick wall
• be bang on
• be barking mad
• be barking up the wrong tree
• be batting a thousand
• be batting on a sticky wicket
• be baying for blood
• be before time
• be before your time
• be behind the eight ball
• be behind the times
• be behind the wheel
• be below par
• be below the belt
• be below the breadline