Oy. I’m afraid you’ve hit on one of my linguistic pet peeves.
An argumentum ad hominem is the fallacy of evaluating an argument based on features of the person advancing it, rather than on its own merits.
If somebody were saying, “Ron Paul is a nasty racist. Therefore, his argument for the gold standard must be bogus,” then that would be an argumentum ad hominem.
On the other hand, if somebody says, “Ron Paul is a nasty racist. Therefore you shouldn’t vote for him for President,” then that’s not an argumentum ad hominem. The issue here isn’t an argument, but rather whether somebody personally ought to occupy a particular political position. Details about the history, personality, and character of a candidate for political office are certainly salient to whether or not you should vote for them, since presumably when you vote for someone you are (inter alia) relying on them to do at least some of what you want them to do while in office, and whether that trust is well-founded depends in part on what sort of person they are.
So while the allegations that have been made against Ron Paul are certainly personal attacks, they are not “ad hominem attacks.” Ad hominem arguments are never cogent. But personal attacks may be uncalled-for or called-for, as the case may be, depending on whether the allegations made in the course of the attack are well or ill-founded.
As far as the allegations that have been made against Ron Paul’s history and character go, I think they’re a pretty mixed bag, but certainly the video doesn’t respond to any of them. Plenty of cornfed military veterans and doctors from Texas have been nasty racists, too. If it’s supposed to be showing that he’s not an ogre, then it seems to me that it’s just evading the issues that have been raised in favor of talking about something else, and then capping it off with a note of adulation that borders on the surreal.
I will say that I have played the video several times nevertheless because I like the old-timey music in the background.