Then argue that they should give you a research assistantship sight unseen and without any evidence of your abilities or potential. Do this with several professors so that they will be sure to know you are insincere. Sit around waiting for someone to pick you. Once you have an advisor, you have to make sure that you get maximum benefit out of the experience. Take an active part in defining your research and in what you learn.
TEAM WORK is a valuable part of successful research.
When given a task to do by your advisor, even if it seems like grunt work, go all out doing it. Don't be afraid to ask questions, it's how you will learn. Request bi-weekly meetings with your advisor at some point after candidacy. This is necessary to make sure you get started on a productive topic. Finally, if you decide that you've made a mistake and that you can't work with your advisor, proceed decisively but carefully.