A lot of people inside the Beltway are tut-tutting about the recent campaign focus on Mitt Romney’s personal history — his record of profiting even as workers suffered, his mysterious was-he-or-wasn’t-he role at Bain Capital after 1999, his equally mysterious refusal to release any tax returns from before 2010. Some of the tut-tutters are upset at any suggestion that this election is about the rich versus the rest. Others decry the personalization: why can’t we just discuss policy?

And neither group is living in the real world.

First of all, this election really is — in substantive, policy terms — about the rich versus the rest.

The story so far: Former President George W. Bush pushed through big tax cuts heavily tilted toward the highest incomes. As a result, taxes on the very rich are currently the lowest they’ve been in 80 years. President Obama proposes letting those high-end Bush tax cuts expire; Mr. Romney, on the other hand, proposes big further tax cuts for the wealthy.

The impact at the top would be large. According to estimates by the nonpartisan Tax Policy Center, the Romney plan would reduce the annual taxes paid by the average member of the top 1 percent by $237,000 compared with the Obama plan; for the top 0.1 percent that number rises to $1.2 million. No wonder Mr. Romney’s fund-raisers in the Hamptons attracted so many eager donors that there were luxury-car traffic jams.

What about everyone else? Again according to the policy center, Mr. Romney’s tax cuts would increase the annual deficit by almost $500 billion. He claims that he would make this up by closing loopholes, in a way that wouldn’t shift the tax burden toward the middle class — but he has refused to give any specifics, and there’s no reason to believe him. Realistically, those big tax cuts for the rich would be offset, sooner or later, with higher taxes and/or lower benefits for the middle class and the poor.

So as I said, this election is, in substantive terms, about the rich versus the rest, and it would be doing voters a disservice to pretend otherwise.

In that case, however, why not run a campaign based on that substance, and leave Mr. Romney’s personal history alone? The short answer is, get real.

Look, voters aren’t policy wonks who pore over Tax Policy Center analyses. And when a politician — say, Mr. Obama — cites actual numbers in a speech, well, there’s always a politician on the other side to contradict him. How are voters supposed to know who’s telling the truth? In fact, earlier this year focus groups given an accurate description of Mr. Romney’s policy proposals refused to believe that any politician would take such a position.

Perhaps in a better world we could count on the news media to sort through the conflicting claims. In this world, however, most voters get their news from short snippets on TV, which almost never contain substantive policy analysis. The print media do offer analysis pieces — but these pieces, out of a desire to seem “balanced,” all too often simply repeat the he-said-she-said of political speeches. Trust me: you will see very few news analyses saying that Mr. Romney proposes huge tax cuts for the rich, with no plausible offset other than big benefit cuts for everyone else — even though this is the simple truth. Instead, you will see pieces reporting that “Democrats say” that this is what Mr. Romney proposes, matched with dueling quotes from Republican sources.

So how can the Obama campaign cut through this political and media fog? By talking about Mr. Romney’s personal history, and the way that history resonates with the realities of his pro-rich, anti-middle-class policy proposals.

Thus the entirely true charge that Mr. Romney wants to slash historically low tax rates on the rich even further dovetails perfectly with his own record of extraordinary tax avoidance — so extraordinary that he’s evidently afraid to let voters see his tax returns from before 2010. The equally true charge that he’s pushing policies that would benefit the rich at the expense of ordinary working Americans meshes with Bain’s record of earning big profits even when workers suffered — a record so stark that Mr. Romney is attempting to distance himself from part of it by insisting that he had nothing to do with Bain’s operations after 1999, even though the company continued to list him as C.E.O. and sole owner until 2002. And so on.

The point is that talking about Mr. Romney’s personal history isn’t a diversion from substantive policy discussion. On the contrary, in a political and media environment strongly biased against substance, talking about Bain and offshore accounts is the only way to bring the real policy issues into focus. And we should applaud, not condemn, the Obama campaign for standing up to the tut-tutters.