Rep. Maxine Waters of California tweeted that President Donald Trump should be "imprisoned & placed in solitary confinement" on Tuesday over his attacks against the intelligence community whistleblower who filed a complaint against him.

The whistleblower wrote that Trump used "the power of his office to solicit interference from a foreign country in the 2020 U.S. election" in a July 25 phone call with Ukrainian President Volodymyr Zelensky.

While Trump is attacking the whistleblower as "fake" and claiming the complaint was based off secondhand information, the substance of the complaint was confirmed by the White House's own memo summarizing the call.

Waters, who has served in Congress since 1991, holds a powerful position as Chairwoman of the House Financial Services Committee and is one of Trump's most vocal critics.

But her claim that Trump should be imprisoned and put in solitary confinement is at odds with the now-mainstream position held by most experts and progressive Democrats that solitary confinement is cruel.

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Rep. Maxine Waters of California was one of the first congressional Democrats to call for an impeachment inquiry into President Donald Trump, which the House formally launched last week.

And in a Tuesday tweet, Waters took her criticisms a step further and said that Trump should be "imprisoned & placed in solitary confinement" over his frequent attacks against the intelligence community whistleblower who filed an explosive complaint against him.

The whistleblower wrote that Trump used "the power of his office to solicit interference from a foreign country in the 2020 U.S. election" in a July 25 phone call with Ukrainian President Volodymyr Zelensky shortly after withholding $400 million in military aid to Ukraine previously approved by Congress.

The complaint said that in the call, Trump him to open an investigation that would hurt the reputations of 2020 presidential candidate and former Vice President Joe Biden and his son Hunter, who served on the board of a Ukrainian gas company.

Read more: 2 key facts refute Trump's conspiracy theories about the Ukraine scandal

Much of the substance of the complaint was confirmed by the White House's own memo summarizing the call. After telling Zelensky that "we do a lot" for Ukraine, Trump asked him for "a favor" by looking into both Hunter Biden's business dealings and CrowdStrike, the cybersecurity firm once hired by the Democratic National Committee.

Former federal prosecutors told Insider that in addition to constituting possibly impeachable offenses, Trump pressuring a foreign government to act for his benefit could violate campaign finance regulations or even rise to the level of bribery or misappropriation of taxpayer funds if he used the military aid as a bargaining chip.

As the House ramps up their investigations into Trump and his administration, Trump has escalated his rhetoric against the anonymous whistleblower, calling them a "fake whistleblower" and saying that he is actively trying to figure out and unmask their identity, which could put the whistleblower's safety in jeopardy.

Read more: Trump says he's trying to unmask the Ukraine call whistleblower, in possible violation of federal law

Waters, who has served in Congress since 1991, holds a powerful position as Chairwoman of the House Financial Services Committee and is one of Trump's most vocal critics.

Last summer, Waters found herself in hot water after encouraging people to publicly harass and call out Trump administration officials in public places, saying, "if you see anybody from that Cabinet in a restaurant, in a department store, at a gasoline station, you get out and you create a crowd. And you push back on them."

But her claim that Trump should be imprisoned and put in solitary confinement is at odds with the now-mainstream position held by most experts and progressive Democrats — and a number of Republicans — that solitary confinement is cruel, unnecessary, and can even amount to torture.

Read more: Alexandria Ocasio-Cortez says Paul Manafort shouldn't be held in solitary confinement, calls the method 'torture'

Last year, a group of Democratic Senators introduced a bill, The Solitary Confinement Reform Act, which aimed to limit the Federal Bureau of Prisons' use of solitary confinement "to the briefest term and under the least restrictive conditions possible."

And prominent progressive Rep. Alexandria Ocasio-Cortez of New York publicly spoke out against former Trump campaign chairman Paul Manafort being held in solitary confinement at Riker's Island while awaiting mortgage fraud charges.

"A prison sentence is not a license for gov torture and human rights violations. That's what solitary confinement is. Manafort should be released, along with all people being held in solitary," she wrote.