Ever since Ronald Reagan posed the killer question to voters in a 1980 debate with then-President Jimmy Carter — "Are you better off than you were four years ago?" — challengers to incumbent presidents have tried to repeat the Reagan magic.

Even when a humming U.S. economy would seem to make the line less potent, it's been pulled out of storage and dusted off, as when Sen. Bob Dole, the 1996 GOP nominee, used it to little avail against then-President Blll Clinton.

But with a weak economic recovery fueling some voters' doubts about President Obama, 2012 could be a productive year for the Reaganesque line of attack. And Mitt Romney, the presumptive Republican presidential nominee, is indicating that he plans to use it, but with variations.

Romney's tweak is to not just to compare economic indicators in 2008 to 2012 but to frame the case against Obama as the alleged falloff between what he promised as a candidate and what he has delivered as a president.

On Wednesday, Romney was in Charlotte, N.C., a key November battleground where Democrats will be holding their national convention in August. The presumptive GOP nominee delivered what was likely to be one of numerous "prebuttals" to the message he anticipates Democrats will deliver when they gather to renominate the president.

Romney repeatedly hit the theme that Obama laid out in his 2008 convention acceptance speech: that voters could measure progress by whether people could find jobs that allowed them and their families to lead lives that met their economic expectations.

Romney said:

"... Virtually nothing he has done has made it more likely for people to get jobs. And so, for three-and-a-half years, we've had unemployment above 8 percent. He set the measure; he has failed by the measurements he set. You won't hear that at this convention, but you're going to hear it at ours..."

In case there was any doubt about the strategy, Ryan Williams, a Romney spokesman, told reporters on a Wednesday teleconference call: "We're going to pose the question to voters, are you better off now than you were when Obama took office?"

Meanwhile, during a visit to another important battleground state, Ohio, the city of Elyria to be exact, Obama offered his own version of the "Are you better off than you were four years ago." Except he expanded the time period from four to 12 years, that is, the entire presidency of George W. Bush.

Speaking of congressional Republicans and of Romney, too, though not by name, Obama said:

"... They keep telling us, well, if we just weaken regulations that keep our air and water clean and protect our consumers, if we just cut everybody's taxes and convert these investments in community colleges and research and health care into tax cuts especially for the wealthy, that somehow the economy is going to get stronger — and Ohio and the rest of the country will prosper. That's the theory."Ohio, we tested this theory. Take a look at what happened in Ohio between 2000 and 2008. It's not like we didn't try it. And instead of faster job growth, we had the slowest job growth in half a century. Instead of broad-based prosperity, the typical American family saw their incomes fall by about 6 percent. Outsourcing, rampant; phony financial profits all over the place. And instead of strengthening our economy, our entire financial system almost collapsed. We spent the last three-and-a-half years cleaning up after that mess. So their theory did not work out so well. Maybe they haven't been paying attention, but it didn't work out so well."

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