The Justice Department sent a letter on Monday to House Judiciary Chairman Jerry Nadler (D-N.Y.) providing details of its review of the intelligence gathering activities that took place before and during the FBI's investigation of the Trump campaign.

Why it matters: Defenders of President Trump have long demanded that the "investigators be investigated," with the president himself accusing the U.S. intelligence community of engaging in an attempted coup to overturn the results of the 2016 election.

"The Review is broad in scope and multifaceted, and is intended to illuminate open questions regarding the activities of U.S. and foreign surveillance services as well as non-governmental organizations and individuals."

The big picture: Trump has granted Attorney General Bill Barr the authority to unilaterally declassify any information he chooses as he investigates whether the U.S. intelligence community improperly surveilled the Trump campaign leading up to the 2016 election. The U.S. Attorney for the District of Connecticut John Durham has been appointed to lead the investigation.

Between the lines: The language in the letter is likely to intended to mitigate some of the fears about Barr's new declassification powers, stressing that DOJ will work closely with the intelligence community to protect sources and methods.

Notably, the letter does not mention the term "spying," which Barr and many Trump allies have used when discussing surveillance of the campaign — language that has prompted significant backlash from Democrats and some national security officials. Instead, DOJ refers to "intelligence-gathering and investigative steps directed at persons associated with the Trump campaign."

Go deeper: What the Mueller report tells us about Trump and Russia