The results of a new NY Times/CBS News poll about Americans’ views on tax policy includes one interesting nugget that may help define the path of this year’s presidential election.

First they asked, “Do you feel you pay more than your fair share in federal income taxes, less than your fair share, or is the amount you pay about right? A little more than half of the respondents chose “about right,” while a third said “more than fair share.” The numbers didn’t change from Democrats to Republicans to Independents.

Then they asked “Do you feel upper-income people pay more than their fair share in federal income taxes, less than their fair share, or is the amount they pay about right?” This is where the differences became apparent — 70% of Democrats said “less,” while only 37% of Republicans said “less.”

But here’s where we get to the important number. Among those identifying themselves as “Independents,” 58% believed that the rich aren’t paying enough in taxes. That’s a big number, 58%, and it’s from the group that will decide this year’s election — those who have no allegiance by party, the swing voters.

Income equality wasn’t even on the map as a campaign issue until the Occupy Wall Street movement began last fall. But now, with stories like Mitt Romney’s tax rate, and unless some catastrophic story comes along (an attack on the US, a natural disaster, etc.), this will be one of the defining issues of the year. The candidate that convinces those 58% will win in November.