IOWA: Hermann Cain falls

The gold-standard in Iowa polls -- The Des Moines Register's -- will show that Herman Cain has faded to just 8% support among likely caucus-goers.

It's a double whammy of concern over the Ginger White affair (47% think he's the most likely to have a scandal in the White House), and primarily, concern over all his stumbles on the issues.

27% think he's the least knowledgeable in the field (frankly, a surprisingly strong showing considering China, Libya, Palestine etc), and that tops everybody in a bad way.

The Register won't release the full poll results until this weekend, so it's too early to see where his support has migrated.