It is evidence that a serious primary challenge from a major Democratic party figure in this election cycle would have had an excellent chance of succeeding: Obama lost 40% of the vote in two Democratic primaries yesterday (Kentucky and Arkansas), without a serious challenger.

In Kentucky, where there was no challenger at all, 42% of voters chose “uncommitted” in preference to Obama.

Of-course, one major reason that there was no serious challenger to Obama in the Democratic party this cycle is that history and conventional wisdom teach that when an incumbent president has a serious challenge of that nature he is likely to go down to defeat in November (in recent history see Jimmy Carter, George H.W. Bush). Therefore even making such a challenge would have been seen by many as not only disloyal but self-destructive to the party’s chances of keeping the White House.

However, yesterday’s results raise a question: What’s the difference—serious challenger or no—if the grass roots of the party is clearly so unhappy with the individual at the top of their ticket?