DES MOINES, IOWA — Republican presidential contender Herman Cain, hoping for a strong finish in the Iowa caucuses, is hoping to follow the lead of another candidate who came from nowhere to win the caucuses and, eventually, the White House: Barack Obama.

Like President Obama in 2007 and 2008, Cain is presenting himself as the anti-Washington, anti-establishment candidate who is such a long shot to win the Republican nomination that even his most egregious public flubs — whether it’s his threat to electrify a fence on the border or his flip-flops on abortion — are insufficient to rattle his momentum.