Based on their 2015 returns, the Clintons don’t have that last problem, which may be partially why they feel comfortable using them as a political weapon. “They earn a lot of income and they paid a lot of taxes, that’s the way the system is supposed to work,” William Gale, a co-director of the Urban-Brookings Tax Policy Center in Washington, D.C., told me. And it is a lot of income: In 2015, the Clintons made roughly $10.6 million—down from $28 million in 2014—and paid more than $3 million in taxes, for an effective federal income tax rate of more than 30 percent. (The campaign calculated a rate of 34.2 percent. But CNN reports it’s 30.6 percent without including their self-employment taxes—and that’s the figure tax experts would typically use.) Nevertheless: “The headline here is they paid over 30 percent of their income in [income] taxes,” Gale said. “There’s no middle-income family that pays 31 percent of their income in income taxes.”

The returns reveal where the Clintons’ money came from last year, most of which Hillary Clinton spent on the trail after kicking off her campaign in April 2015. The Democratic nominee made roughly $3 million off her books—the latest of which is 2014’s Hard Choices—and more than $1.4 million in speaking fees. Her husband made money in a similar fashion: about $29,000 from his books, about $5.25 million from speaking engagements, and more than $1.5 million in consulting fees. Together, the Clintons donated a little over $1 million to charity, the bulk of which went to their family’s Clinton Foundation. Her running mate, Tim Kaine, and his wife, Anne Holton, reported over $300,000 in income.

The way the Clintons made their money last year translates to their high tax rate, Gale said: They are “paying a much higher rate than, say, Mitt Romney did in 2012 or Warren Buffett does, because those people’s income is all in the form of capital gains.” Capital gains are generally taxed at a lower rate. Romney, the former Republican presidential nominee, took in $13.69 million in 2011 and paid $1.9 million in taxes, The Washington Post reported in 2012. His effective tax rate: just 14.1 percent. Monica Prasad, a Northwestern University sociologist who focuses on taxes, noted in an email that the Clintons’ rate may be higher, too, because “she’s not taking advantage of all the deductions and exemptions that other high earners take advantage of.”

The release of candidate tax returns has been a campaign ritual for decades. With Clinton’s 2015 returns now public, the political pressure on Trump to reveal his own is sure to increase, as her team intended. Romney, a multimillionaire many times over, took months of heat in 2012 for not disclosing his latest returns; Democrats accused him of being overly secretive, similar to the way they’ve accused Trump. “I just have to say, given the challenges that America faces—23 million people out of work, Iran about to become nuclear, one out of six Americans in poverty—the fascination with taxes I’ve paid I find to be very small-minded compared to the broad issues that we face,” Romney said in August 2012, a month before releasing his 2011 documents. Romney is now among those questioning Trump’s decision to withhold his taxes.