Politicians like to have a character to refer to in their stump speeches to dramatize their abstract disagreements with their opponent's position -- a widow without health care, a Wall Street banker with a fat bonus, a plumber -- but after unrelenting emphasis on Mitt Romney's career at Bain, President Obama has made his opponent and prop one and the same. The ad the Obama campaign released Saturday, "Firms," got a lot of attention for its soundtrack, which is Romney singing "America the Beautiful" like a non-professional singer. But it's the tagline that comes at the end, after the camera pans over exotic locales with headlines about Romney's offshore accounts, that really matters: "Mitt Romney's not the solution. He's the problem."

No one seems to think there's anything illegal in Romney's tax returns. Indeed, the Republican rationale for releasing them is that the details of his finances can't be any worse than what their candidate is currently weathering. Ron Paul told Politico on Tuesday, "Politically, I think that would help him." He follows former Mississippi Gov. Haley Barbour, Alabama Gov. Robert Bentley, Bush adviser Matthew Dowd, Weekly Standard's editor Bill Kristol, conservative columnist George Will, former Republican National Committee chair Michael Steele, and Fox News' Brit HumeSteve Schmidt, who ran John McCain's campaign in 2008 when Romney was vetted as a possible running mate, said there was nothing disqualifying in his returns. The worst-case-but-still-possible scenario, according to Bloomberg Businessweek's Josh Green, is that Romney paid no taxes in 2009. That would look bad politically, but it wouldn't be illegal or even immoral.

It would, however, perfectly fit the narrative that Obama has been running on ever since he began his national political career. "Right now, we have a tax code that gives incentives for companies to move offshore. Instead, we must have a tax code that rewards companies that are doing the right thing." That isn't an attack ad, that's state legislator Obama running for Senate in June 2004, as quoted by the Chicago Defender. Running for president in May 2008, he told CNN's Wolf Blitzer, "We have seen a lack of shared prosperity. So, you've got CEOs making more in a day than ordinary workers are making in a year, and it's the CEO that's getting the tax break, instead of the workers." He even pledged in that interview, "I will raise CEO taxes. There is no doubt about it." Since that campaign and at least until 2010, Obama has criticized the Bush tax cuts as "tax cuts for people who don't need them and weren't even asking for them." And last September, in his jobs speech at Congress, he struck a familiar refrain on the lack of fairness in the tax system. "While most people in this country struggle to make ends meet, a few of the most affluent citizens and most profitable corporations enjoy tax breaks and loopholes that nobody else gets.  Right now, Warren Buffett pays a lower tax rate than his secretary -- an outrage he has asked us to fix." Eleven days later, he gave another speech, saying Republicans should have to defend tax "unfairness -- explain why somebody who's making  $50 million a year in the financial markets should be paying 15 percent on their taxes, when a teacher making $50,000 a year is paying more than that -- paying a higher rate. They ought to have to answer for it."

That attempt to make Buffett — a guy who supports Obama — an example of one of the people who benefit from an unfair system didn't go so well. Especially for Buffett's secretary. And in fact, Democrats have struggled since at least 2005 to find the perfect tax villain for their pro-middle class tax argument. 

Until Romney.

Bit by bit, often fueled by his own attempts to deflect the story of the day, Romney has been helping to make this caricature stick. When Romney gave in to pressure to release tax information for the last two years, the returns showed that Romney paid that exact same low 15 percent rate Obama had mentioned. Plus, part of that was a $77,000 deduction for expenses related to his wife's horse sport. The Romney campaign spin was that there was nothing unusual about that, which is exactly what 2004-2012 Obama has been saying. To absolve himself of blame for lay-offs and outsourcing Romney said he didn't have anything to do with management decisions at Bain after February 1999. When it became clear that he was still legally in control of the company until 2002 and still is paid millions by it, Romney was lured into admitting he gets paid for nothing.

Obama doesn't say that Romney's a terrible person. These are the rules. Obama says that people like Romney are not paying their "fair share," and that the tax code gives people incentives to do things like send factories to China. This is the problem with America he's been talking about. And now he's got a face and a name.

The Bain attacks aren't the sort of character attacks you see in presidential campaigns. (Think John Kerry and the windsurf picture or the Swift Boat ads.) They synthesize a message that is central to Obama's political identity. He can list all of Romney's offshore dealings in his "Firms" ad, which got more than a million hits on YouTube in just a few days, and attack his character simply by reiterating his policy positions. Or there's the ad by Priorities USA, a pro-Obama Super PAC, called "Stage." ABC News' Jonathan Karl reports this is the most popular ad the group has done so far, with more than a million hits since it premiered June 23. "More significant," Karl writes, "a person at a Republican group that has tested Democratic attacks on Romney told ABC News the ad is potentially the most devastating yet." It's a blend of attacks on both the Republican nominee's biography and what they say are his policies. Ampad worker Mike Earnest explains how after Bain bought the plant, the workers were told to build a 30-foot stage on the factory floor with no explanation why. A couple days later they found out the reason: so Bain people could stand on it and tell them all they were fired. Now Romney is on a different kind of stage, being held up for inspection.