Nadler justified his action based on the lack of response to formal requests for hearings from House Republicans.

On November 30, Nadler was one of 16 Democrats serving on the House Judiciary Committee who made a request to Representative Bob Goodlatte, the committee chair, asking for hearings into possible conflicts of interest resulting from the Trump family's businesses, and the then-President Elect's plan to have his children run his businesses.

House Democrats followed up with a letter to Speaker of the House Paul Ryan on January 12 and a second request to the Judiciary Committee on January 24, saying:

"We believe that the Committee has an obligation to examine the application of these conflict-of-interest laws to both the President and his cabinet. Because President Trump insists on maintaining an interest in his business holdings, we also request an investigation of the legal structure and practices of the so-called "trust" managed by his two oldest sons."

House Republicans have neither responded nor acknowledged the Democrats' requests. As of this morning, a spokeswoman for Goodlatte declined to comment on whether Goodlatte plans to take up Nadler’s new resolution.

The committee that receives the Resolution of Inquiry is required by law to respond to the resolution within 14 days. If there is no response, the representative requesting information can bring the request to the full House of Representatives for a vote. It is one of the few ways for a minority party to move an issue out of a committee without approval from members of the majority party.

If Nadler's Resolution of Inquiry moves to the full House, it is almost certain that the Republicans will vote it down. This puts those representatives on the record as opposing learning more about Trump's business conflicts and the administration's relationship with Russia. That could cost them in the 2018 election.

Should the House Judiciary Committee or the full House approve the resolution, the Executive branch would be required to turn over copies of any document, record, memo, correspondence, or other communication of the Department of Justice, including the Office of Legal Counsel, or any portion of any such communication, that refers or relates to—

(1) any criminal or counterintelligence investigation targeting President Donald J. Trump, National Security Advisor Michael Flynn, Paul Manafort, Carter Page, Roger Stone, or any employee of the Executive Office of the President;

(2) any investment by any foreign government or agent of a foreign government in any entity owned in whole or in part by President Donald J. Trump;

(3) President Trump’s proposal to maintain an interest in his business holdings, while turning over day-to-day operation of those interests to his sons Donald J. Trump, Jr., and Eric Trump;

(4) President Trump’s plan to donate the profits of any foreign governments’ use of his hotels to the United States Treasury, including the decision to exclude other payments by foreign governments to any other business holdings of the Trump Organization from that arrangement;

(5) the Foreign Emoluments Clause as it may pertain to President Donald J. Trump or any employee of the Executive Office of the President; and

(6) any of certain specified federal statutes governing conflicts of interest as they may pertain to President Donald J. Trump or any employee of the Executive Office of the President.

These documents would likely be the beginning of the case to impeach the president. The last time a Resolution of Inquiry was used was 1995 during the presidency of Bill Clinton, who was impeached by the House of Representatives on charges of perjury and obstruction of justice, but was later acquitted when the Senate could not reach the 2/3's majority needed to fully process his impeachment.