It's an overstatement to call Mike Gravel a minor Democratic presidential candidate. But it seems that he's finally found a way to set himself apart from the pack: by crafting the most befuddling campaign ad in history.

His campaign spokesman explained to us the intent behind the ad, in which Gravel stares silently into the camera lens for a full minute, then walks off into the distance, pausing only to hoist a rock into a lake: "It's interpretational."

Reader interpretations of Gravel's ad are welcome.

Update: TPM Reader HS sees Gravel's opus as an existential statement on pop culture:

The key to the ad is the person in the background with the Members Only jacket (I think that is what it is.) It is a homage to the final scene in The Sopranos. The ad, like Gravel's campaign, has no point because life is pointless.