The latest Washington Post polls in Ohio and Florida underscore the trouble Mitt Romney is having in gaining traction on the economy, the one issue he was certain would work for him. That makes this as good a time as any to give some credit to my Post colleague Greg Sargent. He was once a voice in the wilderness, challenging the Romney campaign’s theory of how a backward-looking referendum on a troubled economy would help him defeat President Obama — a theory that, in fairness to Romney, was shared by a significant number of political scientists and practitioners.

First the polls, which give Obama a 52 percent to 44 percent lead over Romney among likely voters in Ohio, and a 51 percent to 47 percent lead in Florida. (Note that Obama is above 50 percent in both states.) Three other Post colleagues, Dan Balz, Jon Cohen and Chris Cillizza, have done a fine job of analyzing the meaning of these numbers, but I want to focus on just the economic findings.

On the one hand, as Chris notes, 55 percent of registered voters in Florida and 56 percent in Ohio say that things have “gotten pretty seriously off of the wrong track” in the country. No surprise, given the national unemployment rates and the mortgage problems that so many Americans are facing. Yet the Post also finds that 52 percent in Florida and 53 percent in Ohio approve of Obama’s handling of the economy. More than that: When the voters were asked which candidate they trust to handle the economy, Obama led Romney by seven points in Ohio and by five points in Florida.

All sorts of things have happened to help Obama, including an apparent improvement in the electorate’s mood about the economy, dueling conventions that ended up helping the Democrats and oodles of advertising. But these numbers suggest that Greg has been right on his underlying point about how voters look at the economy.

As he wrote nine days ago, “[T]he Romney campaign remains wedded to a strategy premised on the idea that these voters can be persuaded that Obama flatly failed on the economy. The word ‘failed’ is now ubiquitous in ads from the Romney campaign and from the [Karl] Rove-founded Crossroads GPS. The Romney team’s driving assumption remains that, once voters come to their senses about the depth of Obama’s failure, they will opt for the alternative without being too picky about the specifics he is offering.”

In fact, as Greg has argued, voters take “a more nuanced and longer view of the situation” and “appear willing to factor the situation Obama inherited into their thinking.”

It is not fashionable to credit voters with a penchant for nuance or the ability to take the long view. But fashion is wrong about this. So I would define the Sargent Theorem as the idea that voters are more subtle in their judgment of economic questions than the conventional wisdom allows. If voters were just casting ballots on economic conditions and right track/wrong track numbers, Romney would be in far better shape.

Republicans seem to be acknowledging this. Thus Bill Kristol’s widely quoted declaration on Fox News: “If this election’s just about the last four years, that’s a muddy verdict. Bush was president during the financial meltdown. The Obama team has turned that around pretty well.”

There’s also this: If the Romney campaign’s old theory about the economy is right and Greg’s is wrong, why is Romney now talking so much about foreign policy? Should Obama hold his current leads and prevail, this election will challenge quite a few electoral models rooted almost entirely in economic determinism. That is what Greg has been doing all along.