Senator Bernie Sanders, the Democratic socialist who’s built a career promoting policies to raise taxes on millionaires and billionaires, said he plans to make public his federal tax returns by April 15, the annual filing deadline.

Sanders of Vermont has said he’ll release 10 years of returns, and disclosed this week that his literary fame of recent years has catapulted him into the ranks of top earners he’s derided for decades.

“I wrote a best-selling book,” Sanders told The New York Times this week. “If you write a best-selling book, you can be a millionaire, too.”

The senator refused to release his full tax returns when he vied for the Democratic presidential nomination in 2016. He’s contending again in 2020 as one of the front-runners, and is attempting to manage the disconnect between decades of rhetoric about the “top 1 percent” and his own position within that group.

When he ran against Hillary Clinton in 2016, Sanders released a lone return, from the 2014 tax year. Since then, Sanders has published three books, including “Our Revolution: A Future to Believe In” and has gone from a small-state senator with ideas mostly seen outside the mainstream, to one of the most recognizable politicians in the U.S.

‘Political Liability’

“The Democratic base is likely to be harsher on politicians who have more wealth. It’s a political liability for Sanders,’’ said John Wonderlich, the executive director at the Sunlight Foundation, an open government group. “For Trump, the liability is if he doesn’t have as much as he said he does.’’

The anticipated release of Sanders’s returns comes as attention on presidential contenders’ tax information is at an all-time high. President Donald Trump broke with a 40-year long tradition by not releasing his returns when he ran in 2016. Democrats have speculated that Trump isn’t as rich as he claims — the Bloomberg Billionaires Index puts his worth at $2.8 billion, mostly from New York high-rises and golf courses — or has foreign business ties that could compromise his independence.

Other Candidates

Democratic candidates, including Senators Kirsten Gillibrand of New York and Elizabeth Warren of Massachusetts, have already released several years of returns, and have pressured their opponents to be transparent in order to draw a contrast with Trump.

On Wednesday, Warren released her 2018 tax return that showed that she and her husband, Bruce Mann, earned more than $900,000 last year. She released a decade’s worth of returns a year ago.

The Treasury Department sent a letter to House Democrats on Wednesday responding to a request to release six years of Trump’s personal and business returns. The letter said Treasury needed more time to review the request and was concerned that a release would be a violation of privacy, despite a law allowing the chairman of the House Ways and Means Committee to review the return of any taxpayer.

Sanders has already revealed some of the haul from his book-writing. He reported more than $880,000 in royalty income on his Senate financial disclosure in 2017. The year before he said he had more than $860,000 in royalty income.

Sanders, 77, also listed three retirement accounts owned by his wife Jane, 69, a former university administrator. The upper value of those accounts is $815,000.

Sanders’s returns won’t show how much wealth he’s accumulated in total, but will show the trajectory of his income over the past decade, as well as indicating whether he personally benefited from Trump’s 2017 tax overhaul, which cut the top individual rate to 37 percent from 39.6 percent.

“Bernie should frame this as ‘Yeah, I’m a millionaire and people like me should be paying more taxes,’” said Brad Bannon, a Democratic consultant in Washington.

Sanders has floated several plans that would expand the estate tax so it would apply to estates worth as little as $3.5 million. He’s also proposed to tax capital gains income at higher than ordinary rates for top earners, and increase the top marginal tax rate on individuals to 52 percent.

Bannon said Democrats need to release their tax returns, but then they need to move on to talking about other issues rather than focusing on how Trump hasn’t released his.

“It’s not politically productive to beat up on Trump,” he said. “Democrats do a lot better when they focus on the environment, Medicare for All or gun violence.”

Bloomberg News