I've made up my mind that I don't want to discuss politics with one specific friend
Why don't you want to discuss politics with them?
We disagree on everything and we know we will never change each other's mind.  It is a waste of time.
It is okay to have difference opinions from friends.  And it is okay to agree to disagree.
I have another friend who agrees with me on everything and we share pretty much the same thoughts so it is perfect.
I believe that it's healthy discussion for all of your to partake in debating with different views. You will be able to get more perspectives, even if you don't agree with it! So how about arranging a friendly debate between you all?