"Politicians love to use the term, because it's vague and connotes an image of regular American people." said Dennis Gilbert, a sociology professor at Hamilton College and author of "The American Class Structure in an Age of Growing Inequality." He said, the varying uses of "middle class" on the campaign trail are "dishonest, and it's absurd."
In recent months, the phrase has been popping up with increased frequency. Referring to the election as a "make-or-break" moment for the middle class, Obama used the term repeatedly in his July 9 speech calling for an extension of "middle-class" tax breaks for families making less than $250,000, or $200,000 for individuals — basically everyone but the top 2 percent. He mentioned the phrase seven times at a fundraiser Tuesday in San Antonio.
Romney has suggested that the upper bounds of the middle class include families earning $200,000. He's pushing an extension of the Bush-era tax cuts for everyone, including the wealthiest 2 percent. Romney's campaign seeks to highlight a weak economy that he says is a "kick in the gut to the middle class," with a new video this week attacking what he calls an Obama record of "political payoffs and middle-class layoffs."
Just Wednesday, Republican House Speaker John Boehner stepped into the fray with a comment that Obama "doesn't give a damn about middle-class Americans who are out there looking for work."
Responded Obama spokesman Jay Carney: The middle class is the "principal preoccupation" of Obama's presidency.
The meaning of "middle class" has grown even harder to parse following a populist Occupy movement that for months protested high unemployment and income inequality with a rallying cry of "We are the 99 percent."
Formal definitions vary, but few academics would say it covers more than 60 percent of Americans.