In a new wave of revelations about how President Trump came to fire FBI Director Jim Comey, one fact may matter most in the long run.

What's new: According to the N.Y. Times' Michael Schmidt and Maggie Haberman, Vice President Pence was in the Oval Office on May 8 when Trump "announced that he had decided to fire Mr. Comey," which he did the next day, and read from an aide's "angry, meandering" draft memo outlining a justification.

More detail, from the WashPost's lead story, matching the NYT: "At the Oval Office meeting, ... Trump described his draft termination letter to top aides who wandered in and out of the room, including then-Chief of Staff Reince Priebus, White House Counsel Donald McGahn and senior adviser Hope Hicks."

from the WashPost's lead story, matching the NYT: "At the Oval Office meeting, ... Trump described his draft termination letter to top aides who wandered in and out of the room, including then-Chief of Staff Reince Priebus, White House Counsel Donald McGahn and senior adviser Hope Hicks." "Pence arrived late, after the meeting had begun. They were also joined by [the author of the draft, senior policy adviser Stephen] Miller and ... Jared Kushner, both of whom had been with Trump over the weekend in Bedminster [N.J.]. Kushner supported the president's decision."

after the meeting had begun. They were also joined by [the author of the draft, senior policy adviser Stephen] Miller and ... Jared Kushner, both of whom had been with Trump over the weekend in Bedminster [N.J.]. Kushner supported the president's decision." Why it matters: That gives Pence more visibility than was previously known into what we have told you is one of the dumbest political mistakes in the modern era, since it precipitated the appointment of Special Counsel Bob Mueller.

Schmidt and Haberman broke the story yesterday that Mueller has obtained a draft of a letter (never sent) "which Mr. Trump had composed with Stephen Miller," giving "an unvarnished view" of why he was planning to fire Comey:

"McGahn, ... the White House counsel, [was concerned by] references to private conversations the president had with Mr. Comey, including times when the F.B.I. director told Mr. Trump he was not under investigation in the F.B.I.'s continuing Russia inquiry."

... the White House counsel, [was concerned by] references to private conversations the president had with Mr. Comey, including times when the F.B.I. director told Mr. Trump he was not under investigation in the F.B.I.'s continuing Russia inquiry." "McGahn successfully blocked the president from sending the letter ... to Mr. Comey. But a copy was given to the deputy attorney general, Rod J. Rosenstein, who then drafted his own letter.

blocked the president from sending the letter ... to Mr. Comey. But a copy was given to the deputy attorney general, Rod J. Rosenstein, who then drafted his own letter. "Rosenstein's letter was ultimately used as the Trump administration's public rationale for Mr. Comey's firing, which was that Mr. Comey had mishandled the investigation into Hillary Clinton's private email server."

What Trump's lawyers can argue: These were Miller's views, not Trump's. What matters is the advice he got from his lawyers, who told him he did have grounds for the dismissal, and prepared the justification.

Why this is a massive problem for White House credibility: This is more evidence — as if we needed it — undercutting Trump's letter to Comey explaining his firing, which doubled as the president's first public explanation. He wasn't accepting any recommendation. Trump wanted to do this, and had stewed about it.

for White House credibility: This is more evidence — as if we needed it — undercutting Trump's letter to Comey explaining his firing, which doubled as the president's first public explanation. He wasn't accepting any recommendation. Trump wanted to do this, and had stewed about it. As the WashPost delicately puts it: "[T]he Oval Office discussion suggests that Pence and other top aides who echoed the initial public explanation for Comey's ouster did not provide a full accounting of Trump's decision process."

P.S. Cover of tomorrow's WashPost Outlook section, "Congress can't count on Mueller's investigation. It should beef up its own," per former Sen. Bob Graham (D-Fla.), who co-chaired the 9/11 committee: "[T]he House and Senate intelligence committees must quickly begin planning for post-Mueller scenarios."