I understand this is a question that easily comes into client's mind, especially if it is an area of importance to her/his own life. I might not be able to work comfortably with someone sharing a total opposite political view, and it would not be the actual voting, but the values would show through everything: how s/he treats people, comments stuff (not necessarily political but just general stuff going on) and so on. If a T is so called blank slate then maybe not, but I would not work with a blank slate either. I knew how my T votes way before she told me. Or not exactly knew, but was almost certain. And I was correct. So maybe you will find out later, maybe only in your heart or because she tells you one day.