After all, if Hillary doesn't actually have any dirt on the Obamas, the next best thing would be to invent a fable that's reported and speculated on at length by righties. That has the dual advantage of allowing falsehoods (that benefit Hillary) to circulate -- and then presenting her (or other Democrats) with the opportunity to blame the "vast right wing conspiracy" for spreading and popularizing them.
Paranoia? Perhaps. But you know the old saying -- "Just because you're paranoid, doesn't mean they're not out to get you."