What Constitutes A Stolen Election?

While the two Democratic candidates continue to battle it out, I believe some people are already preparing to call this "a stolen election" regardless of who ends up winning/losing.

I know many people would cry foul if McCain came out on top in November, but it looks like I am now beginning to see the same patterns of pseudo disenfranchisement in the works on the Democratic side as well.

For example, if Hillary loses I can see some folks claiming the primaries were rigged.

If Obama loses I can see an even more number of people griping, whining and perhaps even rioting as a result.

I'm sure people are going to gripe regardless of who happens to get elected President, so my question is this:
Which candidate do you suppose would generate the least number of disgruntled and disenfranchised voters should they happen to win in November?

In other words, when it's over and done and the winner has been decided, and it doesn't happen to be YOUR candidate, will YOU cry foul?
Will YOU claim it was a stolen election?

People will gripe regardless of who wins, so be prepared..