If I'm not mistaken, our current order of succession is:
Dick Cheney
Nancy Pelosi
Condi Rice
So, it is possible a non-white-male leader could ascend constitutionally before the people actually elect one.
If the current top 3 all went out at once, but if Cheney takes the top spot he would appoint a new VP... In other words, yes it is possible but dont hold your breath.