A common strategy I've seen is for an opponent to cast doubt by making 50 weak rebuttals. Most of them are obviously logical fallacies, mostly red herrings, yet due to the sheer volume it is easy to get overwhelmed.

Then, when I don't respond to one, my opponent and the peanut gallery are like you didn't respond to your opponent's points, so therefore you lose. I find it difficult to defend against this, because it is distracting. I feel if I respond my opponent controls the argument and we end up fighting over whether or not points C,D, and E are red herrings or not. If I don't, my opponent can claim victory for me not responding.

Often, the claims are so bizarre that it is easy to over look them.

Any advice?