Obama takes the podium Thursday night with a massive challenge: Convince voters who think he has mismanaged the economy – the nation’s No. 1 issue – to support him in November.

The reason Obama must take on this extraordinary feat of persuasion is simple. For more than two years, a majority of Americans have disapproved of Obama’s performance on the economy. And if that trend continues, Obama will need to win a greater share of economic “disapprovers” than Romney needs to win economic “approvers.”

So how, exactly, will Obama convince these voters to join his camp? Arguing that a second term would be different may be difficult. Among those who disapprove of Obama’s handling of the economy now, an August Washington Post-ABC News poll found that just 13 percent say they’re confident that the nation’s economy will get back on track if Obama is reelected.

But Obama has a few lines of argument that might appeal to those who disapprove of him on the economy. The first (and most obvious) is focusing away from the economy. In August, 28 percent of this group said they trust Obama more than Romney “addressing women’s issues.” And while 81 percent of respondents said Obama’s economic performance would be a major factor in their vote, 33 percent also said they consider differences between Democrats and Republicans on women’s issues to be a major factor.

Another pitch is that while Obama has struggled to fix the economy, he is in touch with people’s economic problems, or at least more so than Romney. There’s little room to move here, with just 16 percent of those who are downbeat on Obama’s economic performance nevertheless saying  that the president is better than Romney at understanding people’s economic problems. And a less-than-unanimous 64 percent of Obama disapprovers said Romney is more empathetic.

Lastly, Obama could take the fairness route, a trope he focused on earlier this year. More than a third (36 percent) of those who disapprove of Obama on the economy say that “unfairness in the economic system that favors the wealthy” is a bigger problem than “over-regulation in the free market that interferes with growth and prosperity.”

Some voters who give Obama low economic marks are currently in his camp. In late August, 11 percent of this group said they would support Obama if the election were held today, compared with Romney’s 6 percent support among voters who approve of Obama's economic stewardship. But with Romney holding 47 percent to Obama’s 46 percent among registered voters, that slight edge may not be enough on Nov. 6.