Herman Cain’s scrappy campaign for the GOP presidential nomination is making an impression. From Public Policy Polling of North Carolina: Mitt Romney has the lead in PPP’s first Iowa poll since Mike Huckabee and Donald Trump exited the race, but with six different candidates polling in double digits it’s clear this thing is wide open. Romney polls at 21%. Sarah Palin and Herman Cain are tied for second at 15%. Newt Gingrich is 4th with 12%, Michele Bachmann 5th with 11%, Tim Pawlenty 6th with 10%, Ron Paul 7th with 8%, and Jon Huntsman 8th with 0% (only one respondent...