Democrats have spent three years castigating Donald Trump for not allowing the public to peruse his tax returns in the name of transparency and good governance, but the party's presidential candidates have so far been slow to release their filings.

In fact, just two have disclosed anything recent. Sen. Kirsten Gillibrand of New York publicly released her forms for 2018 on Wednesday, a relatively uncomplicated filing showing $214,000 in adjusted gross income – her $167,634 in congressional salary augmented by a $50,000 payment for her campaign autobiography. And Sen. Elizabeth Warren of Massachusetts has posted all her returns since 2008 on her campaign website, although she hasn't filed for last year.

"The Democratic candidates now find themselves in a potentially challenging spot. They face pressure to release years' worth their returns, to emphasize to energized primary voters how different they are from Trump and how they reject his approach to government service," the Washington Post wrote in detailing how the 2020 field is handling the matter so far. "At the same time, tax returns can sometimes include embarrassing information or disclose data at odds with a candidate's political self-portrait – such as a lofty income that might not sit well with Americans living paycheck to paycheck."

Three other senators – Bernie Sanders of Vermont, Kamala Harris of California and Amy Klobuchar of Minnesota – and former Rep. Beto O'Rourke of Texas have promised to release returns but have not committed to a timetable or a depth of disclosure.

Sen. Cory Booker of New Jersey has given some access to his filings before past elections but has not made clear what he will do this time. And Joe Biden, who is expected to announce his decision within a month, has released tax returns from 1998 through 2015, his penultimate year as vice president.