A good part of that was simply ignoring the poll *results*, and looking instead at their internals. Then, mentally adjusting the skewed results by how skewed the D+x was (D+8, D+12, D+whatever).
Also having the belief that the Fake News sources were totally wrong and blundering hugely. When everything they tried against him blew up in their faces and increased his support, I knew that they were clueless as how to bring down a man not afraid of them and therefore powerless to control events.