The standoff comes just days after reports that President Trump directed his then-Chief of Staff John Kelly to give his son-in-law Jared Kushner a security clearance despite concerns from the intelligence community.
Democrats want more information on what Trump's former lawyer described as "catch and kill" operations to silence people or news stories that could damage Trump's image.
Cummings opened the investigation into White House security clearances shortly after taking over as chairman of the committee. The committee sent letters to 81 people and entities - including the Justice Department, White House, senior campaign officials, Trump Organization officials and Trump's sons - and have demanded responses within two weeks.
Democrats have launched a sweeping probe of Trump, an aggressive investigation that threatens to shadow the president through the 2020 election season.
White House press secretary Sarah Sanders said Monday that the White House counsel's office and relevant officials will review the letter and respond at the appropriate time.
Yet, he did not rule out the possibility that the Trump daughter could eventually be part of the probe. The panel is sending document requests to 81 people linked to the president and his associates.
The longtime lawyer also said he does not believe Mueller's report will show any collusion between the Trump campaign and Russian Federation.More news: Trump Vows To Sign Campus Free Speech Executive Order At CPAC
In addition to the NRA, Nadler also sought documents from the White House, the Trump Organization, Trump's charity, the Federal Bureau of Investigation and Cambridge Analytica, a data company that worked with the Trump campaign and has been investigated by Congress in connection with Russia's election interference efforts.
These hostile actions have spurred some Republicans to cry foul, including Washington attorney Joe diGenova, who suggested today that Trump's DOJ should not cooperate with Nadler's abusive investigation.
Democrats want documents relating to the patronage of Trump businesses, like the Trump International Hotel in Washington, by USA and foreign officials and dignitaries seeking to curry favor with the president.
Schiff also announced he hired Kathy Suber, who served as a government intelligence officer for two decades, and Lucian Sikorskyj, who worked for the National Security Council and served as a senior analyst to North Atlantic Treaty Organisation.
Democrats on the House Intelligence, Oversight and Financial Services Committees have pledged to investigate further.
Nadler said Monday's document requests are a way to "begin building the public record" and the committee has the responsibility to investigate.
The president went off on the House Democrats for allegedly realizing the "only Collusion with Russia" was by "Crooked Hillary Clinton". The person declined to be named to discuss the committee's internal process.
Shedding light on how partial the investigation would be, Nadler told ABC News before he issued the document requests that he's convinced that Trump has obstructed justice.