take (one's) part
To support or part with someone in an argument. You always take your wife's part, even if you don't agree with her! Thank you for taking my part at the meeting. I was starting to feel like I was on my own in there.
take somebody’s ˈpart
(British English) defend or support what somebody has said or done, especially in an argument: Personally I take Emma’s part on this matter.He never takes my part in an argument.