Actually I don't think you need that many to convince President Biden that the border wall needs to stay and additional walls need to be built.

The way I see this.... when the caravan gets close to the Northern border of Mexico I think Biden should go down and personally greet them and tell them they can't cross into the United States right now. I'm sure they will all understand "H.T.B" - "Happy Time Biden" ... and simply walk back home.