The short answer is to try to vote for people who have been consistent with there message. Ron Paul has always been consistent over the last 20 years, plus he's a doctor. Its pretty hard to see any consistency on the democrat side. Maybe Dennis Kucinich. The ASA has just brought a lawsuit against the justice department on 1oth Amendment grounds that the feds have no authority in these states unless the product crosses state lines. Will be an interesting case.