On Tuesday, it was reported that special counsel Robert Mueller wrote a letter challenging Attorney General William Barr over his four-page summary of the Russia investigation, claiming he mischaracterized their findings. Democrats believe Barr's summary was an intentional attempt to protect President Donald Trump from the report's damaging findings, and many of them are speaking out against Barr. Upon Tuesday's revelation, 2020 Democratic nominee Julián Castro has called on Barr to resign, accusing him of "willfully" misleading the nation "to cover up attempted crimes by Donald Trump." Attorney General Barr willfully misled the American people to cover up attempted crimes by Donald Trump. He should resign his position or face an impeachment inquiry immediately. https://t.co/dTKCMccF7X — Julián Castro (@JulianCastro) April 30, 2019 SLIDESHOW: TOP DEMOCRATS RUNNING FOR PRESIDENT IN 2020 Additionally, Rep. Jerrold Nadler (D-N.Y.), the chairman of the House Judiciary Committee, is calling for the release of Mueller's letter. Nadler adds how Barr "must answer for this" and that Mueller "must be allowed to testify." Mueller has written a letter objecting to Barr’s summary of his report because it “did not fully capture the context, nature and substance of the investigation.” I have demanded the letter & Barr must answer for this. Mueller must be allowed to testify. https://t.co/gylocOsYlv — (((Rep. Nadler))) (@RepJerryNadler) April 30, 2019 Senate Minority Leader Chuck Schumer (D-NY) tweeted out how the "misleading nature" of Barr's testimony and press conferences last month is now "even more glaring," concluding that "it's time for Mueller to testify publicly." In light of Mueller's letter, the misleading nature of Barr’s 4/10 testimony & 4/18 press conference is even more glaring. Barr must bring the letter with him when he testifies in the Senate tomorrow. And it’s time for Mueller to testify publicly. Now.https://t.co/d3lObZSQBE — Chuck Schumer (@SenSchumer) May 1, 2019