"In a lot of ways, it's the standard party line — Democrat, working-class rhetoric, Republican, business class," says Mitchell McKinney, professor of communication at the University of Missouri.

"Both are playing to the base. ... Obama has to address those disparities in the economy without seeming that he is anti-business, anti-capitalist. ... Romney wants to tout the making of money and successful working of the capitalist system but not highlight in any way the downside. In that sense they both have fine lines they're trying to walk."

Both men have tripped on their own rhetoric.

There was Obama's recent retreat from his assertion that "the private sector is doing fine" and Romney's declaration that "corporations are people." In coming months, McKinney says, the candidates, surrogates and big-money political groups will repeat certain words and phrases "so America comes to accept their narrative as reality. Clearly, words do matter."