Complicating matters further, the two demographic groups — upscale and blue-collar white voters — can’t necessarily be courted with the same message; a populist pitch that motivates the blue-collar vote may alienate upper-income voters just as strongly.

Consider it an exercise in symmetrical warfare: a campaign in which the two parties’ nominees are equally hobbled with the sliver of voters who are actually persuadable…

Strategists privy to internal polling on both sides of the 2012 race say that higher-end suburbanites — particularly white women — are perhaps the most closely divided persuadables. One Republican operative involved in 2012 strategy put it this way: “We are going after moderate, upscale people, who maybe for the first time voted for a Democrat for president [in 2008] and are rethinking that.”…

One Republican strategist deep in swing-state territory called that “one of the problematic things” about Romney: “It’s blue-collar, independent voters, more populist voters, that might — maybe with a labor tie or something like that — be persuaded to be a Democrat and stay with Obama because of Romney’s just not being completely trusted on the social values front.”