This is reasonable debate fodder. It's not a great strategy for widespread TV ads with his name and fact on them, in my opinion.

The problem is that people will see it as "just" Obama vs. Clinton, if it's associated with him. That automatically makes it noise to most people who aren't passionate about this.

But Clinton vs. Democrats, that's a different thing. It's harder to ignore.

Associating it with Obama only works for people who are already predisposed to like Obama. People predisposed to like Clinton will just say, oh that Obama, he's attacking that nice Hillary Clinton again.

But frame it as an attack by Democrats against Clinton, and it's much more likely to appeal, because it's not candidate advocacy.