Talk about closing the sale! Starting around time 0:38 you'll see something I never thought we'd see in ads again. But you'll enjoy it more if you let it build to that part. Way to get under Obama's skin!
Now, I cannot be 100% sure that this is real rather than Onion parody. (And doesn't that say something delightful about our politics at this stage?) David Roberts, of Grist, who alerted many people to it, is skeptical. But if you check some of the other ads the campaign has posted, like this one, it's not that far off. The "Mark Block" speaking in this ad looks very much like the online pictures of Mark Block of the Cain campaign.
And, "I am not a witch," which I was sure at first was clumsy parody, turned out to be "real" too. Not to mention "Demon Sheep." So I'm daring to bet this is legit, but we'll see. Meanwhile, celebrate the parade of democracy.