When you make up the list of guests for that very special dinner, be sure to clarify the status of the expected guests. Don't confuse bores with boors.
Bores are OK. The normal, run-of-the-mill bore is harmless, just a tedious, wearying sole who means well but has nothing to say of significance. You're lucky because he'll just sit quietly through dinner and the post-dinner conversation. Pity the poor woman whom you place next to him, but he's probably as bored as she is.
One solution is to invite two bores and have them sit next to each other at one end of the table. They may even have a reasonably good conversation together.
On the other hand, you might get away with inviting one rude, insensitive boor to dinner. Your guests should be able to ignore one.
But never, never invite two cretins to the same dinner. The seating arrangement itself will create an act of war. The blighters will be at each other, and striving to outdo the other, before the first course is served.
A "Boor War" is not the way to go. Instead of a polite hour of conversation touching lightly around the fringe of politics, sports, good television and the like, the louts will see each subject as an opportunity to express their strange conspiracy theories on whatever the subject is at the moment. Your dinner will dissolve into chaos as the two boors tangle on every issue.
So, avoid the Boor War. Limit the guest list to one boor only. Better yet, lose that invitation!