Mike Allen reports on the fallout from Trump’s firing of Comey:

The answers to why Trump canned Comey are becoming clear: The president was filled with grievance about the FBI probe and acted on impulse without clearly thinking through the fallout, numerous sources tell me.

The consequences are also becoming clear: This one quick decision put everything at unnecessary risk, from his legislative agenda to his public standing — and potentially his presidency.

“It is a debacle,” said one Republican in constant touch with the West Wing. “They got everything — timing, rationale, reaction — completely wrong.”

I can readily believe that Trump would do something self-destructive on impulse without thinking about the consequences, but the more remarkable thing about this episode is that no one in his inner circle was able to alert him to the obvious dangers of what he was about to do. That confirms that the president is terrible at assessing risk, and it also tells us that none of his closest advisers is effective in steering him away from making huge blunders. This is just the latest in a string of wounds that Trump has inflicted on himself, but it appears to be one of the largest and most damaging to date. Every new administration makes mistakes, but I haven’t seen any that has engaged in so much gratuitous self-sabotage as this one does.