So who are the real working-class heroes in this Presidential race?

Now that the conventions are over and the presidential campaign’s endgame begins, it has become abundantly clear that both the Obama and McCain campaigns are locked in a feverish race for the title of Most Ordinary.

Having stumbled with white working-class voters who don’t seem to trust Obama’s working-class roots, he is running as fast as possible from the elite educational background that helped launch his extraordinary rise to power. Despite their Harvard Law pedigrees, Obama and wife Michelle have taken pains to tell Americans that they’re really just ordinary folks.

McCain, the U.S. Naval Academy graduate who married into one of the richest families in Arizona, who’s come dangerously close to being unmasked as an ordinary-man phony (he can’t recall how many of the eight homes across the country he actually owns), can trot out Sarah Palin as a genuine gun-tot’n, snowmobile-riding lady who went to public schools and graduated from a land-grant university.

The salient facts of Palin’s political potency are now clear: She’s extraordinarily ordinary. Hockey Mom; Alaska oil field worker’s devoted spouse and soon-to-be grandma to the child of her pregnant 17-year-old daughter; an American “just like us,” who also happens to be a governor of a rugged western state.

As an outsider to the precious Washington elite, Palin in a few short days became the GOP’s front for its newfound populist rhetoric.

Palin’s big coming-out speech at the Republican National Convention hit the right populist chords, and the sea of comfortably white delegates and in the St. Paul audience wildly approved, woo-hooing Palin’s tele-prompted “gotcha” lines aimed at Barack Obama and the Democrats.

“Perfect populist pitch, “ as CBS’s Jeff Greenfield described Palin’s performance.

Populist pitches aside, who are the real working-class heroes in this race?

In terms of identity politics, the Obama-Biden ticket would be hard-pressed to beat Palin on that score. Neither Biden nor Obama have enough Grandma or Scranton, Pennsylvania stories in the queue to overcome Palin’s rugged Western backstory.

What’s more, having an unmarried 17-year old daughter who’s five months along is powerfully middle-American. (Springer’s waiting on the line, Sarah. He wants to do a show.)

In an age when ordinary Americans will vote a wealthy Connecticut Yankee, George W. Bush, for president because he did a good Texas drawl, the Democrats simply can’t match what the Republican image machine can make of Palin’s story.

Image really is everything. That’s really too bad for the Democrats because, it turns out, they actually have represented working-class economic interests better than the Republicans since the Second World War.

In fact, the empirical evidence is eye opening. In an impressive new study, Larry M. Bartels, a professor of political science at Princeton, found that across the spectrum of poor to upper-middle economic classes, inflation-adjusted family incomes grew significantly higher under Democratic administrations than Republican ones.

Consider the 20th, 40th, and 60th percentile of family incomes, for instance. These include the solidly middle- and lower-middle class voters both political parties claim to represent.

When Democrats were in power from 1948 through 2005, average annual growth of family incomes for the 60th percentile of families was three times the growth under Republican rule. At the 40th percentile, the annual growth in real family income under Democrats grew was 2.5 percent versus just 0.8 percent under Republican administrations.

At the 20th percentile, the gap was widest. Under Democrats, family incomes for these upper-middle class Americans grew at 6.5 times the annual rate than under Republicans: That’s 2.6 percent compared to a meager 0.4 percent.

So the party of tax and spend liberals, as conservatives never tire of complaining, do a much better job than the party of alleged limited government and low taxes of actually protecting the economic interests of ordinary Americans.

By rights, Democrats should own that issue. But two truths should never be underestimated: The cynical ability of the Republican marketing machine to delude; and the proclivity of ordinary Americans to be deluded.