With his new documentary, "Merchants of Doubt," activist filmmaker Robert Kenner ("Food, Inc."), sets his sights on the professional pundits-for-hire who present themselves as experts in their field, but in actuality are just shills for corporations who use them to stall any political action that might improve public health, but hurt their bottom lines.

Starting off with Big Tobacco, the film quickly moves on toward the current "debate" over climate change, showing how a handful of pseudo-scientists have managed to create the illusion of dissention in the ranks of climatologists. With these deniers getting as much media exposure as the people who actually know what they're talking about, they've been remarkably effective in stalling the environmentalist movement. And as one expert states, it took nearly 50 years for any change to effect the cigarette industry, but when it comes to global warming that's too long a timeline -- by that point it will be far too late.

Kenner frequently cuts to his interview with magician Jamy Ian Swiss, who explains various tricks of his trade and ties into the film's overarching motif of magic and sleight-of-hand that function as a pretty effective metaphor for the misdirection corporations and their various minions utilize to mislead the general public. It makes for stylish, swiftly-paced viewing, but "Merchants of Doubt" is at its most effective during its scenes following Bob Inglis, a former Republican congressman from South Carolina, who lost his seat after he had the gall to acknowledge that the science behind climate change is real. As we watch him unsuccessfully attempt to convince a right-wing radio talk-show host, the film gets at some of the infuriating tribal mentality that defines our current political age, leading people to bury their heads in the sand and tune out any information that doesn't reinforce what they've already decided to believe.