I am SPOOFE W. Diddly, and I approve of these underpants.
I think the reason the candidate has to ‘approve’ the message is because the commercial is being paid for by another ‘organization’ not directly affiliated with his campaign. This helps keep the finances separated. The approval clip just allows the candidate to be seen in the commercial.
4 out of 5 dentists approve of chewing this message to reduce plaque build-up.