McCain, Giuliani, and Romney have all attracted unwanted attention this week with their pledge to continue the federal government's unpopular war on medical marijuana patients and providers. The question is "why?" Everyone knows mainstream republican politicians are often a tough sell when it comes to drug policy reform, but given massive public support for medical marijuana, their callous position appears politically unwise and thus more difficult to explain.

First, it helps to clarify how narrow and simplistic their argument really is. The McCain/Giuliani/Romney consensus on medical marijuana is grounded in the claim that "other medications" are available and should be used instead. This one argument virtually encompasses the totality of their opposition to medical marijuana. It is their only talking point, which is why they move on quickly to the next topic after saying it.

Still, I don't believe this argument actually tells us very much about their true motivations. When Mitt Romney recommends "synthetic marijuana" to a wheelchair-bound patient, it becomes clear that he understands the medical efficacy of the drug. Indeed, these "other medications" are often derived from synthetic cannabinoids, so the debate is clearly not over whether marijuana has medical properties. We've moved beyond that, thankfully.

At this point, it becomes a question of how patients should be acquiring and administering their medicine. Giuliani and Romney both faltered when the patients they encountered explained that they were allergic to pharmaceutical alternatives to marijuana. If they take these patients at their word, they must then confront the insufficiency of these drugs and recognize the unique predicament in which certain patients find themselves. Perhaps this new information will sink in, but that is all beside the point.

Ultimately, McCain, Giuliani, and Romney have access to all the same facts about medical marijuana as everyone else. Their problem is not a misunderstanding of the issue. They've met and spoken with the patients. They know doctors are recommending it. Their real concerns have nothing whatsoever to do with the medical efficacy of marijuana. They are worried about something else entirely:

"But having legalized marijuana is in my view an effort by a very committed few to try to get marijuana out in the public and to ultimately legalize marijuana. It's the wrong way to go." – Mitt Romney

"I believe the effort to try and make marijuana available for medical uses is really a way to legalize it. There's no reason for it." – Rudy Giuliani

This tells us everything there is to know about opposition to medical marijuana from republican presidential candidates, and for that matter, the Drug Czar himself. The whole anti-medical marijuana machine is merely a conspiracy to prevent the outright legalization of marijuana. Its adherents are fearful that telling the truth about the drug's medical value will pave the way for a shift in public attitudes about marijuana in general. They dread the "marijuana lobby" and will concede nothing to it, even if doing so forces them to take unpopular and transparently flawed positions on medical use.

Cynically, they focus on the role of marijuana legalization advocates in promoting medical access, while ignoring the much larger constituency of medical marijuana supporters who don’t advocate recreational legalization. That is why support for medical marijuana from mainstream organizations such as the American Nurses Association and the American Public Health Association is ignored, while the pro-legalization Marijuana Policy Project's position is cited routinely.

Of course, when the truth about medical marijuana becomes a political hostage in the broader legalization debate, it is legitimate patients rather than marijuana activists who suffer the consequences. Fortunately, the rise of internet video has given voters a front row seat in this enduring and increasingly ugly debate. The next victims in the war on medical marijuana may be those candidates who would sacrifice the seriously ill to drug war politics.