How so?
Now that Thompason’s gone, he’s got no one at all. If he just pouts and says he’ll not participate, that’s as good as supporting Obama/Hillary/Edwards nominee.
So no matter what he does he’ll get criticized.
I don't see anyone criticizing Thompson for not endorsing anyone.
Huckabee is the greatest threat to the Republic of all candidates running. To endorse him, for any reason, leaves your conservative credentials shattered.