CAPITOL HILL – U.S. President Donald Trump and some congressional Republicans have accused Democrats in the House of Representatives of failing to conduct a transparent impeachment inquiry. They allege Democrats are impeaching a duly elected president behind “closed doors,” hiding the process from the American public.

Here’s what you need to know about the controversy.

Are House Democrats impeaching Trump behind closed doors?

House Democrats have begun the impeachment process by holding an impeachment inquiry, in which the House formulates specific charges of misconduct against the president. This impeachment inquiry is a fact-finding process which can lead to an impeachment, but the two are not the same.

Impeachment will occur if the House of Representatives holds a full floor vote passing Articles of Impeachment. The U.S. Constitution grants the House the ability to impeach the president and other officials for “Treason, Bribery, or other high Crimes and Misdemeanors.” The term “high crimes and misdemeanors” is not defined by the Constitution but could be interpreted to include abuses of power.

Congressional Democratic leaders have said allegations that Trump temporarily withheld nearly $400 million in congressionally-approved U.S. aid to pressure Ukrainian President Volodymyr Zelenskiy to assist in digging up political dirt on Democrats in the 2020 election campaign would be considered an abuse of power if proven true.

While Democrats have said they will continue to hold closed hearings as they gather evidence, they also have said they will go public and release more details in the coming weeks.

Is this process different from prior impeachment inquiries?

In previous impeachment inquiries, the House Judiciary Committee took the lead in investigating allegations and held impeachment hearings in public. But House Speaker Nancy Pelosi designated the House Intelligence Committee the lead committee to investigate the allegations against Trump.

Due to the sensitive nature of the Intelligence Committee’s work, hearings are almost always held in private, behind the closed doors of a secure area known as the SCIF, or Sensitive Compartmented Information Facility. SCIFs are very closely monitored and secured to ensure that the sensitive materials discussed within are not obtained by foreign governments or spies.

Intelligence Committee Chairman Adam Schiff has the ability to determine if a hearing can be held in public and did so recently when the acting director of national intelligence, Joseph Maguire, testified last month about the whistleblower allegations that triggered the formal launch of the impeachment inquiry.

Schiff has said his committee will release transcripts of interviews with witnesses and hold open hearings at the appropriate time in the probe.

Are House Democrats denying Trump “due process” as some Republicans allege?

Democrats argue the impeachment inquiry is roughly comparable to the process of a grand jury in the United States. Grand juries hear evidence during depositions — witness interviews that allow jury members to determine the validity of an accusation before a trial. Under that process, witnesses are interviewed privately  in part, to avoid coordination or adjustment of testimony.

Members of three House committees involved in the inquiry are allowed into the SCIF during these depositions. In total, close to a quarter of the entire U.S. House of Representatives is allowed to be in these depositions. Of those 109 House members, 47 are Republicans who sit on the committees. Many of the House Republicans who forced their way into the SCIF last week to protest the lack of due process were already allowed to be in the room and had attended previous depositions.

Under this process, the House committees  like grand juries  will hear depositions and determine if the evidence warrants drawing up Articles of Impeachment. Those articles will then be debated in public on the floor of the House. If the House passes Articles of Impeachment, the Senate will be required to hold a trial in public to determine if Trump should be removed from office.

Is the impeachment inquiry legitimate?

Trump argues his administration is not required to comply with subpoenas — legally binding orders from House Democrats requesting documents needed for the investigation — on the grounds the impeachment inquiry is not legitimate until the House of Representatives votes to formalize it.

In a letter earlier this month, Trump’s White House counsel, Pat Cipollone, wrote, “The House of Representatives has never attempted to launch an impeachment inquiry against the President without a majority of the House taking political accountability for that decision by voting to authorize such a dramatic constitutional step.”

The House did vote to formalize impeachment inquiries for Presidents Richard Nixon and Bill Clinton, but there is no rule in the Constitution requiring such a move. Pelosi told reporters, “There’s no requirement that we have a vote. And so, at this time we will not be having a vote.”

The Constitution does not specify any rules for the process, simply granting the House of Representatives “the sole Power of Impeachment” and the Senate the power to try “all Impeachments.”