Originally Posted by Snicklefritz
What's a good counter-move if someone is doing this to you in a race?
First off, don't provide the gap to give the other rider the idea.
Otherwise, do the reverse, on the other side. Just scoot up until your brake lever is pretty much pushing a butt cheek of the rider you're following. If everything is going right, you will be on the downwind side anyway, and can ride there pretty much indefinitely. The incoming rider will be out in the wind and unable to get into a good drafting position. If the the other rider still decides to come in, you can provide the same treatment, and quickly take the wheel back.
That's one nice thing about riding in TX. There's ALWAYS a crosswind