Twenty states allow marijuana use for medical conditions ranging from multiple sclerosis and glaucoma to AIDS and post-traumatic stress disorder.
That's despite the fact the 1970 Controlled Substances Act listed cannabis as a schedule 1 drug — along with heroin, LSD and mescaline — that has no medical benefits and a high potential for abuse.
There's no doubt people abuse pot — just as some people abuse alcohol — but the initial classification was intended to be temporary while a commission appointed by President Nixon further studied the drug.
In 1972, the National Commission on Marihuana and Drug Abuse, chaired by former Pennsylvania Gov. Raymond Shafer, released its findings:
"Neither the marihuana user nor the drug itself can be said to constitute a danger to public safety," the authors wrote.
"Therefore, the Commission recommends ... possession of marijuana for personal use no longer be an offense (and) casual distribution of small amounts of marihuana for no remuneration, or insignificant remuneration no longer be an offense."
There it was. The report put pot in its proper perspective and offered reasonable advice to address legitimate potential problems.
If only Nixon had followed it (granted, he had other things on his mind at the time).
Instead, the president and members of Congress declared all-out war on a relatively minor issue and created much larger societal ills – an entire criminal industry, drug wars, prison overpopulation – that we're still dealing with some 40 years later.
It has taken us much longer to come to our senses than it took our great-grandparents to overturn Prohibition, but it is happening.
The Justice Department last year signaled it would not challenge states that allow medical marijuana or the two that have legalized recreational pot use.
And Attorney General Eric Holder recently said members of Congress won't get a fight from him or the president if they want to remove marijuana from the list of most dangerous drugs.
It's a move long overdue, but it's becoming more urgent as new marijuana-based medicines show promise for patients who have exhausted all other treatments with no relief.
Removing marijuana from the list of schedule 1 drugs wouldn't make it legal to buy and smoke pot for pleasure – but it would clear the way for researchers to study its medical benefits without running afoul of the law.
That, apparently, is the cover some state lawmakers require before they can support medicinal use in Pennsylvania.
Compassion for fellow citizens was enough for legislators in other states, but not so here.
We wish that wasn't the case.
But, sadly, not even pleas from desperate parents whose children suffer daily can sway a majority to abandon a mistake made a generation ago.
Gov. Tom Corbett is so far removed from the level-headed Shaffer, his GOP predecessor, that he wouldn't support medicinal marijuana even if a doctor said it was his 2-year-old grandson's last hope.
That's a rare and frightening form of irrationality.
Better to hope for relief at the federal level than try to reason with people like this.