After days of sniping over timing and scale, both Sen. Scott Brown (R-Mass.) and Harvard Law Professor Elizabeth Warren (D) have both released several years of past tax returns.

The fight echoes the one between President Obama and former Massachusetts governor Mitt Romney at the national level. Except both Brown and Warren are kind of Obama, and they’re both kind of Romney.

Elizabeth Warren holds up a poster of herself as Sen. Scott Brown (R-Mass.) looks on. (Michael Dwyer/AP)

Warren’s income peaked earlier. She and her husband (also a Harvard Law professor) made $981,000 in 2009 and $954,721 in 2010. In 2011, their combined income dropped to $616,000. Her income comes from teaching and consulting as well as the government salary she drew through mid-2011 as an adviser to the president on consumer affairs, and before that, as leader of a panel overseeing the bank bailout.

Both candidates pay higher tax rates than Romney, who has been attacked by Obama’s campaign as a “beneficiary of a broken tax system,” and higher rates than Obama himself did in 2011. Brown paid between 21 and 28 percent; Warren between 26 and 29 percent.

But Brown is criticizing Warren for not volunteering to pay a higher rate, an option for wealthy Massachusetts residents.

Just as Obama’s campaign is pressuring Romney, Brown is pushing Warren to reveal more than she would like. The senator released the past six years of returns; Warren initially committed to two years and then expanded to the past four, her time in public service.

Brown’s campaign manager argued that Warren is hiding “important and potentially revealing information” by not exposing more. Meanwhile, Warren’s campaign argued that by pushing for a Friday release, Brown was trying to bury the story.

Combine Brown and Warren’s wealth and you’d still be nowhere near Romney territory. But both are emphasizing their populist appeal on the stump, and their high incomes could damage those brands.

Brown’s likable everyman image helped him win the 2010 special election; it’s at the heart of his campaign and it’s what Democrats are focused on.

Even before the tax returns came out, the Massachusetts Democratic Party put out a video declaring that “it’s clear there’s a millionaire under that $675 barn jacket, with as much as $100,000 in big oil and big bank stocks, and real estate estimated at more than $1.6 million.”

Warren has aimed to compete on the same turf, emphasizing her humble Oklahoma roots and her empathy with the middle class. Brown’s campaign manager has labeled her an “elitist hypocrite” who is “firmly entrenched in the same ‘1 percent’ she rails against.”

One presidential-level fight that likely won’t be echoed here: charitable donations. Neither candidate stands out as a charitable giver. Last year Brown gave 3.2 percent of his income to charity; Warren gave 2.8 percent.*

* Correction: This post originally mischaracterized Brown’s charitable giving. He gave 3.2 percent of his income to charity last year, not on average over the past six years.