That's what happened to Kander in Missouri. Obama's face morphed into Kander's. It was borderline racism, at least subconscious, frankly.
Um, what?
You have to actually see the ad to see what I mean, and I don't use the racist card nearly as much as many on the left do, mind you. They literally just turned Kander's face into Obama by slowly morphing his face into his and darkening his skin. When was the last time an ad like that happened to a white person being morphed into another white person's face? I'll wait. There's actually a relevant social paychology experiment to this to, but I have to look it up.
Do you have a link to that ad? I haven't heard anything about this. But even if it exists, I doubt it was intended to be racist. Kander is actually very liberal (and pretty close to Obama and Clinton), so linking him to a liberal Democratic president isn't racist.
EDIT: Oh, here is the story.
So yeah, it wasn't just Obama, but also Clinton, Pelosi and Sanders. Wonder why you left out that part?
http://edition.cnn.com/2016/10/14/politics/missouri-battleground-senate-race-jason-kander-roy-blunt/