That “What’s the Matter with Kansas?” sentiment goes to the heart of the demographic paradox that has defined the 2012 presidential campaign. Obama is positioning himself as a protector of the working class, even as blue-collar whites are showing historically low support for him. Likewise, Warren’s rhetoric appealing to the working class resonates predominantly with some of the wealthiest liberal Americans, who have donated generously to her campaign. But it’s been a challenge for her to connect with many of the average Joes, in part because her background as an academic and government official. Unlike Romney, Brown has a well-worn reputation for connecting with those folks.

Perhaps Romney will be a much easier foil than Brown on the convention stage. Democrats are confident about using the convention to cast Romney as an out-of-touch plutocrat and believe Warren’s background advocating for consumers in her brief role with the Consumer Financial Protection Bureau makes her an ideal prosecutor. In a best-case scenario for Democrats, Warren could emerge as a hit among the “Walmart moms,” that oft-cited swing demographic who could play a decisive role in a close election. Several Democratic operatives pointed out that the speech will coincide with the NFL season opener, making it likely the audience would be more female and more in Warren’s sweet spot.

But in a worst-case scenario, sounding too strident could risk a Democratic version of Pat Buchanan’s infamous 1992 convention speech, in which he argued there was “a religious war going on in our country for the soul of America.”