If you're the host, you can't be everywhere at once and having helpers in the rest of the house can be just as important as having helpers in the kitchen. Employ one of the more trustworthy older children to entertain the younger ones, for instance. With the above-mentioned relatives, perhaps someone that knows both of them could help steer the conversation away from any political topics. It's a time honored strategy to keep family from behaving like the savages they are. Most people are much better behaved in front of strangers than they are with their own family members.
P ass the tofu turkey, please.
I'm particularly fond of. I'm a vegetarian for both moral and health reasons, but I don't try to force my views on my family members, so I am comfortable with them eating meat in front of me. The problem is that quite often at this and other family gatherings, they fail to consider me when planing the meal. I end up with a rather skimpy selection of bread and vegetables instead of a full meal. If you've got a large family, it's quite possible that they aren't forgetting about your dietary needs on purpose, especially if they don't have to deal with them on a daily basis.