Marijuana laws are a mess, with medical use permitted in almost half the states under their laws but no use allowed in any state under federal law. Voters in Colorado and Washington state have widened the rift, legalizing recreational pot use in those states.

This is a complicated situation, and one that Maine should not drive further out of whack.

But that’s what a bill to legalize marijuana in Maine, proposed by state Rep. Diane Russell of Portland, would do. However well-reasoned her approach, this is really a problem that can’t be fixed at the state level. The federal government should step up, and do so soon.

Russell’s bill seeks to bring marijuana out of the black market and sell it legally so it can be taxed. Sales controlled by the government, like the sale of alcohol,could be denied to minors and would bring tax revenue to the state, Russell argues.

In addition to bringing in revenue, legalization could also save the state money now spent on the prosecution and incarceration of marijuana offenders.

Maine voters have repeatedly shown their support for the medical use of marijuana at the polls, most recently in 2009. Given the chance, they might back a referendum like the ones passed in Colorado and Washington state this year.

But the Legislature is a different story. Lawmakers crushed a similar bill just six months ago, voting this June against it 107-39 in the House. Attitudes may have changed since then, but not so much that this bill could pass without a serious fight. The proposal’s supporters would have to overcome the opposition of a significant portion of the law enforcement and child welfare communities, and possibly even a gubernatorial veto.

And after all that, what would be gained if supporters of legalization succeeded? Not much. It would still be a controlled substance under federal law, and people who bought and sold it would still be subject to federal prosecution.

This is a problem that can be solved only in Washington, and the less time lawmakers in Augusta devote to it, the better.