Documentary filmmaker and unabashed liberal Michael Moore assured MSNBC'S Rachel Maddow on Monday night that conservative Republicans may not be Mitt Romney's biggest foes going into the Michigan GOP presidential primary on Tuesday.

Instead, Moore said a stunt dubbed Operation Hilarity may mobilize Democrats to cast their ballot in one of the nation's only open primary races in order to support a win by Rick Santorum, a move they ultimately believe will lead to the reelection of President Barack Obama come November.

I have to tell you a lot of my Democratic friends will vote for Santorum in something they are calling Operation Hilarity, Michael Moore said at the end of the interview. We do have a good sense of humor in the state of Michigan.

The idea, proposed by the left-leaning Web site The Daily Kos, is intended to keep the Republican primary race in a deadlock in order to tarnish the viability of the frontrunners and ensure a second term for Obama.

The longer this thing drags out, the more unpopular the Republican presidential pretenders become. Just look at Mitt Romney's trajectory, reads a Feb. 15 article, on the site referring to Romney's plummeting poll numbers. Rick Santorum will inevitably follow the same path once he gets properly vetted. Just imagine Santorum, with the far more radical record and a continued inability to raise real money.

The Web site also encourages Democrats in North Dakota, Tennessee and Vermont -- which have open contests coming up -- to step up to the challenge.

The so-called operation is more than a facetious proposal. Several political commentators in Michigan have broached the subject. On Tuesday morning Tim Skubick of Michigan Live predicted that lots of Democrats will cross over and make mischief in the GOP race today.

Americans may be growing increasingly tired of the GOP race, which has been in full gear since last spring. In December, 70 percent of respondents told Gallup they couldn't wait for the 2012 campaign to be over -- weeks before the first primary vote even occurred.

For his part, Santorum seems to be on board with Operation Hilarity. The Santorum campaign has reportedly been placing robocalls to Michigan Democrats where a narrator encourages them to place their vote in the primary to help defeat Romney.

Why is it so important? (Mitt) Romney supported the bailout for his Wall Street billionaire buddies, but opposed the auto bailout. That was a slap in the face to every Michigan worker. And we're not going to let Romney get away with it, it states.