Just when you thought you'd heard every loopy idea to come down the Beltway, along comes news that President Barack Obama wants to tax Christmas trees to -- sit down -- promote them.

Yes, you read that right. "The Hill" reported that the president proposed a 15-cent tax on large scale producers of grown-in-the-ground Christmas trees to fund a Christmas Tree Promotion Board. It seems the artificial variety is cutting into tree producers' and importers' business, according to the Christmas Tree Checkoff Task Force. (The Onion couldn't top this one if it tried.)

Where to start? How about the basics: Tax something more, you get less of it. Large-scale tree producers will pass the tax along to the consumer. While 15 cents isn't a big deal, raising the price of something doesn't increase the quantity demanded.

Moving on to politics, the three biggest Christmas-tree harvesting states, after Oregon, are North Carolina, Michigan and Pennsylvania. These are states Obama won in 2008 and needs to hold onto in 2012.

Like all government policies designed with special interests in mind, this one has its exemptions. Those who produce or import less than 500 trees annually would be exempt from the assessment, The Hill reports. Just get in line to file an exemption request.

And this, ladies and gentlemen, magnified hundreds of thousands of times a year, is why nothing of consequence gets done in Washington. Talk about missing the forest for the trees.

(Caroline Baum is a Bloomberg View columnist.)