White House counsel Pat Cipollone is correct in saying that the House "has never attempted to launch an impeachment inquiry against the president without a majority of the House taking political accountability for that decision" by passing a resolution.

But such a vote is not required. The House has voted to impeach federal judges without passing a resolution to authorize an investigation, and the House procedure for impeaching judges and presidents is the same. Even so, House Democrats will hold a vote Thursday to clarify the rules for public hearings, even though a federal judge said on Oct. 25 that "a House resolution has never, in fact, been required to begin an impeachment inquiry."

4. Would passing a resolution give Congress authority to get grand jury material, such as evidence gathered during the Robert Mueller investigation?

Not necessarily. A fight over this issue is now in federal court, and the House won the first round.

The House leans on what happened in 1974. After a federal grand jury in Washington finished an investigation of the Watergate scandal, it prepared a special report on its findings and recommended that its work be forwarded to the House Judiciary Committee, which had begun impeachment proceedings.

Judge John Sirica ruled that while the grand jury's work was secret, he had the authority to release the material to the House. He said that the normal reasons for keeping grand jury proceedings secret — such as preventing the escape of someone who might be indicted or insulating the grand jury from outside influence — no longer applied once the grand jury's work was done. And he noted that Nixon did not object to letting the House committee get the material. That's an important fact.

A federal appeals court agreed with Sirica's decision, and the grand jury material was turned over to the House.

Since then, the federal courts have narrowed the power of judges to declare exceptions to grand jury secrecy. Earlier this year, for example, the D.C. Circuit Court of Appeals said in a different case that there's no exception allowing historians to get access. The court said it interpreted what Sirica did in Watergate as allowed under a federal rule that allows giving grand jury material to the House for "judicial proceedings." But that was said in a footnote: It was not the holding in the case, and that comment did not make any new law.

The Justice Department's view is that the issue isn't settled. It said in a recent filing in the current lawsuit that no court has ever squarely decided whether a House impeachment proceeding qualifies as an exception to longstanding rules of grand jury secrecy. And if Trump — unlike Nixon — explicitly objects to turning the material over, that could be a decisive factor.

In late October, Federal District Court Judge Beryl Howell ordered the Justice Department to give the House Judiciary Committee an unredacted version of the Mueller report, along with some underlying materials. She concluded that the requirement for preserving grand jury secrecy was outweighed by the House Judiciary Committee’s need for the material in its impeachment investigation. The Justice Department immediately appealed.

5. Do the president’s lawyers get to participate in the House impeachment hearings?

This point is sometimes misunderstood. After the White House counsel complained that no Trump lawyers have been allowed to take part in the House committee sessions, many commentators said that the criticism was misplaced, because Trump's lawyers would get their chance in the Senate trial, not in the House proceeding. But that's not how it has worked before.