Idk. Maybe. I think Biden has done a great job if you look at his policies, and I would have hoped people were excited about them. I take your comment to say that people are fooled into having more enthusiasm for a candidate with the same policies just becase a different face has been put on them. But there can be other reasons for the enthusiasm. For example, maybe people believe she will do a better job since she is younger and more energetic. And those people think a younger, more energetic candidate makes for a better President even while holding the same political views. If that gets people excited, fine. It may be from being fickle and fooled or may be from a realistic view of how leaders impact the group and how a younger leader could be better.