Thanksgiving dinner will be explosive in some families.
Arguing can be fun. It releases endorphins. The problem is that it can escalate and one of the participants can feel threatened.
One strategy is to have a "safe" word or phrase. If enough people know the safe word then they can distract the parties who are arguing or insert themselves between the two parties.
After considering and discarding various phrases: "Still your president", "Shiffer-brains" "I liked it better when you were a Non-Playing Character", I decided on the safer phrase, "I wanna look at the pumpkin pie". That gives me an excuse to leave the field of battle.
Your mileage may vary.