But Obama, seeking to tap into middle class economic anxiety, has mocked Romney's proposal as "trickle-down tax-cut fairy dust." And this week he called the plan "Romney-hood" or "Robin Hood in reverse."
Surveys suggest Obama's plans resonate with voters.
A Pew Research Center Poll released last month showed 44 percent of Americans believe raising taxes on the wealthiest would help the economy, not hurt it. Just 22 percent believe the opposite. The same poll showed that Americans believe 2-to-1 that Obama's tax proposals would make the tax system more fair, not less.
Democrats say they're also buoyed by private polling in both the presidential election and competitive congressional races that shows strong voter support for the president's tax policies. One Democratic strategist said the internal polls show at least 60 percent of Americans, including independents and some Republicans, backing the notion that the wealthy should pay more in taxes and that the nation's deficit must be reduced through a combination of tax increases and spending cuts.
But Republican strategist Charlie Black, an informal adviser to Romney's campaign, disputes the notion that Obama's arguments are gaining ground.
"The Obama campaign outspent us in June and the first half of July with all those arguments, and the numbers haven't moved anywhere, even in the national polls," Black said.
Whatever the case, Obama's team doesn't intend to move off its tax criticism.
"You can bet the president will be talking about their differing visions for tax cuts up until the moment the polls close on Nov. 6," said Jennifer Psaki, a campaign spokeswoman.
Associated Press writer Josh Lederman contributed to this report.
Follow Julie Pace at http://twitter.com/jpaceDC.