When President Obama sent the justice department attorneys after the medical marijuana distributors in California and Oregon, many of his supporters were shocked. Some folks went to him and said medical pot was a good thing, and the states were cool with it, so there's no reason for the feds to get involved.
Obama told them that there were abuses, pot crossing state lines, people getting it who were not really in need. "But," the pot advocates pointed out, "These folks are going to buy it anyway. If they can't get legal pot, they'll get it illegally on the street." Obama dismissed that as absurd.
After those folks left, some representatives from the Mexican drug cartels, waiting in the next room, came in. They said, "El Presidente, you handled that muy perfecto. Keep up the pressure on those damn amateurs, those fools with the licenses. We are your supporters, and we don't have to show you no stinking licenses. Remember, there's 300 million in campaign contributions riding on you getting rid of our competition."
Obama smiled and assured them that he would uphold the letter of the federal law, that being his constitutional duty, and, "by the way, as you leave, drop off a check with my secretary."