10/09/2012 02:35 pm ET Updated Dec 09, 2012

Etch-a-Sketch as a Long-term Liability

Mitt Romney may have come out of last Wednesday's debate a short-term winner, but did little to solve his biggest long-term challenge in this election: his inability to convince voters they can trust him.

Romney is being credited with the win following a debate in which he benefitted from an abrupt rhetorical move to the center. As many have pointed out, he seemed to disavow much of what he had been saying on the campaign trail over the last two years with regards to taxes, regulation and Medicare, among other subjects.

While Romney's about-face on his core economic philosophy may have helped win him the night, it opened him up to further attacks on his trustworthiness, which PNA research shows is the single most important factor on which undecided voters -- at least those in the West -- will make their decisions.

In polling conducted in late September, we asked undecided voters in Arizona, Colorado, Nevada and New Mexico which candidate characteristics were most important in determining their vote. By far the highest percentage (nearly 4 in 10) said "Is someone they can trust" is the most important characteristic.

At the time, President Obama enjoyed a small but significant advantage over Romney when we asked voters which candidate "is someone you can trust."

By attempting to etch-a-sketch away the last several years of public statements, Romney risks widening the president's advantage in the area of trustworthiness. Given the priorities of the small numbers of voters who remain persuadable, this could be a critical mistake for the Romney campaign.

This tension between Romney's attempt to reinvent himself, and voters' distrust of him will be one of the key dynamics to watch in the campaign's final month.