You' re for Randall, and not your father, for vice president.
"be for""支持,赞同,站在哪一边"
eg: We have got two different opinions. Which arguement are you for?你支持哪种意见?
I' m for more environmental protection because I don' t think the goverment is doing enough.我很支持环保,因为我觉得政府在这方面做得还不够.