Efforts to legalize marijuana for recreational use are gaining momentum in Washington state and Colorado. (Cliff DesPeaux/Reuters)

We don’t expect the teetotaling former Massachusetts governor, who has said he supports the federal ban, to take the leafy bait — but there are a few reasons it might not be such a wacky idea, once the GOP field has shaken out and he’s the last man standing.

First, Paul’s supporters could be quite valuable to the eventual GOP nominee. While they’ve been dismissed as the party’s fringe element, they’re young and enthusiastic — two characteristics the GOP badly needs in a general election. (After all, Romney’s managed to tick off Hispanics, so he’s in need of any constituency he can get his hands on.)

And then there’s Colorado. With medical marijuana shops on nearly every corner and a libertarian-leaning electorate — not to mention its status as a swing state — the Centennial State could tempt Romney to take a seemingly radical turn on drugs.

Pot legalizers note that he could couch his support in terms of a 10th amendment argument — essentially saying it should simply be up to states to decide for themselves. That would allow him to maintain his own opposition to legalization while also giving a shout-out to social conservatives, who love a good nod to state’s rights.

There’s evidence that the idea of pot-legalization is going mainstream — even among Republicans. After all, Pat Robertson endorsed the idea, and approval among voters in recent polls is surprisingly ... well, high.