A Obama/Hillary ticket would mean Obama would have to watch his back constantly. He would know that he could end up in the proverbial Ft. Marcy Park, and that there would be countless ways it could happen.
On the other hand, a Hillary/Obama ticket might have the same situation, because Obama would have reason to think Hillary would want him gone once she was in the White House.
And maybe she would have to watch her back in the same way, you never know with these leftists.
I would hate for the only thing between Hillary and the presidency to be my beating heart.