Special Prosecutor Rober Mueller has reportedly obtained a letter that President Trump and his top policy advisor, Stephen Miller, drafted in the days leading up to the firing of James Comey. It details why Trump was planning on dismissing his FBI director, per The New York Times' Michael Schmidt and Maggie Haberman.

White House counsel Donald McGahn stopped Trump from sending Comey the letter in May. Instead, a letter written by Deputy Attorney General Rod Rosenstein, which discussed Comey's handling of the investigation into Hillary Clinton's personal emails, was sent to Comey on the day of his firing.

Why it matters: Trump's explanations for firing Comey have been shifting from the start, and this letter could provide a more solid basis for his original intent.