With the economy set to be the defining issue of the presidential election, voters are split over which candidate they believe is better suited to advance their economic interests.

According to an ABC News/Washington Post poll released on Friday, 46 percent said President Obama would do more to advance their economic interests, versus 43 percent who named Mitt Romney.

That’s a statistical tie, with the poll’s 3.5 percent margin of error.

Romney has his work cut out for him if he hopes to gain traction among the middle-class voters whose turnout will be critical in battleground states in the Rust Belt and Midwest — 51 percent said Obama would do more to advance the interests of middle-class Americans, compared to 42 who said Romney.

The Obama campaign spent the early weeks of the cycle looking to portray Romney as an out-of-touch corporate financier willing to slash jobs if it meant increased profits for his private-equity firm, Bain Capital. A number of Obama campaign ads have focused on former employees who said they lost their jobs in the wake of a Bain acquisition.

In addition, a solid majority of voters — 65 percent — view Romney as the candidate that would do more to advance the economic interests of wealthy Americans, versus only 24 for Obama.

The president has made the "Buffett Rule," which would require individuals who make more than $1 million a year pay a tax rate of at least 30 percent, central to his 2012 platform to “level the playing field” for workers, and has done so against stiff opposition from Republicans, who blocked the proposition in the Senate in mid-April.

However, additional data in the survey bring into focus the danger Obama faces in making this populist economic pitch — Republicans are looking to paint Obama’s policies as anti-business, and 56 percent said Romney would do more to advance the interests of financial institutions, versus 32 percent for Obama.

The Bain ads have provoked many on the right, and even some Democrats, to criticize the campaign for targeting the free-market financial activities of a private company. Obama has since sought to draw a distinction between the role of private equity and the role of a president.

But while perceived over-regulation of financial institutions might not hurt Obama in the eyes of voters — a plurality in the poll said banking regulations didn’t go far enough — Republicans have argued that the Buffett Rule is a tax on job creators that would stymie economic growth, and Romney is viewed as the more friendly candidate to small businesses, 47 percent to 45 over Obama.

The poll sample was largely made up of voters that described themselves as working class, middle class, or below, and the even split makes them a key and coveted demographic in what is shaping up to be a tight election.