There is no other way to put it: Former F.B.I. Director James Comey tragically botched the investigation into Hillary Clinton, no doubt playing a part in her losing and Donald Trump’s being elected.

But it is also true that Comey may be a linchpin in undoing the mistake he made.

Trump was completely out of bounds when he fired Comey — the man who was leading an investigation into connections between Russia and the Trump campaign — and then bragged to the Russians about the firing.

Last month, The New York Times reported that Trump asked Comey “to shut down the federal investigation into Mr. Trump’s former national security adviser, Michael T. Flynn, in an Oval Office meeting in February, according to a memo Mr. Comey wrote shortly after the meeting.”

“ ‘I hope you can let this go,’ the president told Mr. Comey, according to the memo.”

The question of whether Trump’s ask, Comey’s continuance and Trump’s subsequent firing of Comey constitutes obstruction of justice looms large.