Washington( CNN) Michael Flynn's downfall Friday worsened grave legal and political hazards that represent the most serious threat to any administration for at least 40 years, and could eventually threaten the Trump presidency itself.

The plea deal cut by the fired national security consultant with Special Counsel Robert Mueller undermines much of what the White House has said about the Russia controversy engulfing the presidency.

It means there is now no believable way for President Donald Trump to claim the Russia investigation is a hoax, made up, fake news or a witch hunt.

Comey runs biblical after Flynn plea

Flynn pleads guilty to lying to FBI