The federal government should clarify its position on medical marijuana and remove unnecessary obstacles to state-regulated dispensaries. Medical marijuana is legal in 17 states, and what amounts to federal harassment benefits no one.

The immediate issue is the inability of dispensaries, businesses explicitly allowed and regulated by the state, to use the banking system. That is creating a difficult and dangerous situation for no reason.

The wisdom or benefit of allowing the sale and possession of marijuana for medicinal use was debated statewide, after which Colorado voters approved it with the November 2000 passage of Amendment 20. With that, the legality of medical marijuana became part of the state’s Constitution.

But at the same time, federal law still classifies marijuana as a Schedule 1 narcotic – the same category as heroin – and deems it to have no legitimate use. Under federal law, all sales and possession of marijuana remain illegal. The result is a legal and regulatory mess.

Medical marijuana advocates thought they had found a way around that with the election of President Obama. He said during the 2008 campaign that he favored a more lenient approach to medical marijuana. And as president, he directed the attorney general to come up with guidelines for states that had legalized it. A 2009 memo from Deputy Attorney General David Ogden to U.S. attorneys instructed them not to use federal resources to prosecute “individuals whose actions are in clear and unambiguous compliance with existing state laws providing for the medical use of marijuana.”

Advocates thought that settled the matter. Things, however, are rarely that simple. Financial institutions are federally regulated, and banks handling what federal law sees as the proceeds of illegal drug trafficking could face racketeering charges. Last year, U.S. Deputy Attorney General James M. Cole told banks that anyone involved with money from marijuana sales could be in “violation of federal money-laundering statutes and other federal financing laws.”

With that, dispensary operators are facing unpleasant options. They can try to hide the nature of their businesses from their bank or funnel proceeds through their personal accounts, questionable ideas at best, or they can operate as strictly “cash-only” businesses.

That raises concerns about crime and public safety. As state Sen. Pat Steadman put it this week, “They’ve got bags of pot, bags of cash. It’s a bad situation.”

Steadman was the sponsor of Senate Bill 75, a bill to establish a cooperative banking institution in Colorado to offer banking services to dispensaries. That proved unworkable, in part because it became clear federal action was required. The bill died Tuesday. But the need for some fix is clear.

Colorado has about 600 medical marijuana dispensaries. The Associated Press quotes an industry group as saying the medical marijuana industry employs between 5,000 and 10,000 people. TheNew York Times reported Sunday that Colorado Springs collects $700,000 from pot sales; Denver got $3.4 million in fees and taxes; and Colorado as a whole took in $5 million in sales tax from medical marijuana dispensaries.

That is a fraction of what something such as the gas industry pays in taxes, but in this economy, it is still nothing to sneeze at. It hardly seems too much to ask that dispensary owners be allowed to pay by check. It is unlikely this year, but Congress and the president should act on this. A legal business needs a bank.