I believe it is because they've seen that person as very capable and talented from the beginning. The
more derision, the less likely otherwise uninformed public will vote for them. Even when Hilary was a governor's wife, she was regarded as a future political threat, and many voters bought into the hate and lies that were perpetuated for years. Elizabeth Warren is an example of being targeted, and soon many others will be included, I'm sure. Non-partisan sites are readily available to find out the truth. Why do so many conservatives/Republicans/Tea Partiers/Trump supporters refuse to check out these sites? It's a mystery to me.