President Barack Obama isn't a populist but he plays one on the campaign trail. Like many liberal Democrats, he plays up the down-home rhetoric for votes, but by nature he's a progressive technocrat immanently comfortable trusting the authority of experts. This comes from being the son of an anthropologist and former editor of the Harvard Law Review. This is why he sounded so wooden when attempting to rail against "fat cat bankers," and why he needs Vice President Joe Biden, a natural-born class warrior.

But the president's populist mien stems from more than campaign strategy. It's context, too. Compared to quarter-billionaire Mitt Romney, his Republican challenger in the 2012 presidential election, no-drama Obama appears downright folksy. Sure, working-class Americans don't usually feel kinship with a former constitutional law professor, but that's far better than a guy who owns a dressage champion competing in the 2012 Summer Olympics. It'd be one thing if Romney's horse was a racing steed. Americans understand betting on the ponies. But dressage? First, it sounds kinda French. Second, that means a dancing horse, right?

That's slightly unfair. But Romney isn't helping.

First, he's not being clear about his wealth. He has released only two years of tax returns. This has allowed the Obama campaign to suggest, rightly or wrongly, that he's hiding something. And in fairness, that's a plausible charge given that Romney has cash stashed in the Cayman Islands and Switzerland, and the reason you do that is to avoid the prying eyes of the Internal Revenue Service.

Second, the central claim of his candidacy — that he is an experienced businessman who knows how to create jobs — took a major hit last month after a report in the Washington Post found that Bain Capital, Romney's former Wall Street firm, invested in companies that pioneered the trend of outsourcing jobs.

Romney's reaction was twofold and too dumb — he demanded that the newspaper retract the story (it said no) and he said the reporters didn't know the difference between outsourcing and offshoring. Frankly most people don't, and if you're trying to save face by splitting hairs, good luck to you. You're going to need it.

Third, he rebounds poorly. Parsing "outsourcing" and "offshoring" was just the beginning. Last week, the Associated Press revealed that Romney has investments in a company in Bermuda, raising more questions about transparency and indeed how wealthy Romney actually is. Estimates so far put his wealth at as much as $250m, making him the richest man to run for the White House in recent memory (Obama's wealth is as high as $3m).

And again, Romney stumbled badly: "I don’t manage [those investments], I don’t even know where they are," Romney told a radio station in Iowa, a battleground state. "That trustee follows all U.S. laws, all taxes are paid as appropriate, all of them have been reported to the government. There’s nothing hidden there."

This kind of explanation flies with people who have blind trusts, but not with people who don't have trusts or don't know what trusts are, and sure as hell don't know why they are blind. And anyway, Romney could dispel the ambiguity by releasing more returns just as his father, George, did before making a run for the presidency.

Now Obama is hitting hard: "What’s important is if you are running for president is that the American people know who you are and what you’ve done and that you’re an open book," he told a New Hampshire TV station. "And that’s been true of every presidential candidate dating all the way back to Mitt Romney’s father."

My guess is that Romney won't release more tax returns, because he doesn't want to bring more attention to himself. I say this not because I think he's hiding something (though he may be for all I know), but because Romney wants this election to be a referendum on the president's first term not a choice between him and Obama.

The reason for that is Americans tend to give incumbents the benefit of the doubt, but if Romney can raise enough doubt about the economy — and with a stalled economy on the brink of a double-dip recession, there's good reason for this strategy — he can frame the election as a thumbs-up-thumbs-down vote.

Obama, on the other hand, is doing his best to make this a choice between opposing candidate, parties and ideologies. Yesterday, we saw the latest stage of that strategy when he called for Congress to allow the George W. Bush-era tax cuts for the wealthiest two per cent of income earners to expire at the end of the year.

This is good politics for two reasons. One, most Americans approve of such a measure, partly because taxing the rich lowers the national debt and partly because taxing the rich just feels good. The second reason this is good politics: It puts Romney in a box. Obama highlighted the fact that he himself would be paying higher taxes and that he stood ready to do so. Romney, meanwhile, has said letting the tax cuts expire is bad for small business, which may be true. What's certain is that Obama is setting up a choice.

American voters can choose the rich guy willing to pay more in taxes for the good of his country or the rich guy who didn't.

That, to most Americans, is an easy choice.