It’s a more frequent scenario than one may realize.

According to Roll Call’s Wealth of Congress report, 39% of Congress has a net worth of $1 million or more. Rep. John Delaney (D-Md.), currently in the running for the 2020 candidacy, is reportedly the sixth-richest member of Congress with a net worth of $92.6 million.

But while well over a quarter of lawmakers are millionaires, just 3.6% of the U.S. population enjoy similar riches. Market research firm Spectrem Group found that there are 11.8 million Americans with a net worth of at least $1 million as of 2018.

“Part of the problem with our society is that in order to run for office, you need to be able to take months off and work without pay,” said Morris Pearl, chair of Patriotic Millionaires, a group of wealthy Americans advocating for progressive policy. “And a lot of people with families are living paycheck to paycheck and they can’t afford to do that.”

U.S. Senators are paid $174,000 annually—already more than double the median household income for Americans, which rested just more than $60,000 in 2017—but many have additional wealth from book sales, speaking events, and spousal income that puts them in the 1%. According to the Economic Policy Institute, a family needed to earn at least $421,926 to be considered in this elite category in 2015.

Sen. Bernie Sanders (I-Vt.) saw his income jump from a six-year average of $281,000 to more than $1 million in 2016 after the publication of his book “Our Revolution,” which raked in about $840,000 that year. He and his wife paid a tax rate of 35%, and then went on to earn another $1 million in 2017—again a figure heightened by each of the Sanders’ success in writing.

Sanders, a frequent critic of the elite, defended his newfound wealth in an interview with the New York Times: “I wrote a best-selling book,” he said. “If you write a best-selling book, you can be a millionaire, too.”

In 2018, the Sanders’ gross income dropped to around $561,000. They paid a tax rate of just less than 26%.

“These tax returns show that our family has been fortunate. I am very grateful for that, as I grew up in a family that lived paycheck to paycheck and I know the stress of economic insecurity,” Sanders said in a statement accompanying the tax returns’ release. “I consider paying more in taxes as my income rose to be both an obligation and an investment in our country.”

In truth, Sanders has maintained his stance against shortcuts for the wealthy. He proposes implementing progressive estate tax on multi-millionaire and billionaire inheritances, ending tax breaks on capital gains and dividends for the wealthy, and increasing the marginal tax rate on income above $10 million.

Still, Sanders was criticized for the irony of his financial position: “It’s all very off-brand and embarrassing, but Sen. Bernie Sanders is a millionaire,” reads a piece published on ThinkProgress. Sanders later responded with a letter calling for the progressive news site to end its “counterproductive negative campaigning” and “play a constructive role in the effort to defeat Donald Trump.”

ThinkProgress may have gone too far (the original article included comments about Sanders’ appearance), but it does seem strange: Sanders is a millionaire railing against the billionaires in defense of the working class.

“I don’t think the fact that he made money from selling this book over the last couple years suddenly changes his views,” said Pearl in Sanders’ defense.

“I honestly believe that somebody can understand their constituents who are in a different situation than they are,” Pearl added. “I think that poor people can understand rich people and rich people can understand poor people—if they try and if they want to.”

“There are some that don’t want to,” Pearl continued, referencing Secretary of Commerce Wilbur Ross, who suggested during the recent government shutdown that hungry federal workers take out loans to put food on the table.

Sen. Kamala Harris (D-Calif.) and Sen. Elizabeth Warren (D-Mass.) are striving not to be in this category. Like Sanders, they each have wealth, but support progressive policies.

According to Warren’s tax returns, she and her husband have earned more than $900,000 over the past two years—a combination of her spouse’s role as a professor at Harvard and Warren’s book sales—yet she’s made herself a champion of the middle class.

Warren’s key tax reform proposal is the “Ultra-Millionaire Tax,” which would only apply to households with a net worth of $50 million or more (likely just the 0.1%). While this policy would leave those with Warren’s wealth alone, it implements a 2% to 3% tax on the ultra-rich, potentially bringing in $2.75 trillion over a 10-year period.

Harris is well below the threshold of the “ultra-millionaires,” but she’s certainly the wealthiest of the 2020 candidates who have released tax returns. Harris’ average income in the decade prior to her 2014 marriage was roughly $174,000, with her annual salary peaking at nearly $263,000 just before she left her position as the district attorney of San Francisco. Once she married, however, her husband’s work as a lawyer boosted their household adjusted gross income to more than $1 million each year.

Harris and her husband earned more than $2 million in 2018 and paid a tax rate of nearly 37%. Most of the money came from husband Douglas Emhoff’s work with DLA Piper and Venable, but Harris also earned $320,000 from her book, “The Truths We Hold.” In her 2020 campaign, Harris has promoted a tax cut for the middle class, funded by “reversing this administration’s giveaways to big corporations and the top 1%.”

According to Pearl, wealthy individuals like these senators have to fight for more progressive policies because it’s in everyone’s interest—regardless of wealth.

“I don’t want to live in a country with a few rich people and lots of poor people, because that’s not the kind of country where my kids can grow up and start businesses and do things,” he said. “I’m just as greedy as the next guy, just I’m greedy for a different kind of country.”