Everyone with a video screen knows about the failure to protect Donald Trump from a would-be assassin in Butler, Pennsylvania. But don’t look to Secret Service director Kimberly Cheatle for answers because she doesn’t have any.

That was the bottom line from a House Oversight Committee hearing on Monday. Cheatle said the agency failed in protecting the former President — no kidding — but did little to explain the staggering operational mistakes. She couldn’t illuminate even basic facts about how a young shooter, apparently acting alone, was able to get an AR-15 style rifle within a few hundred feet of the former President.

We know law enforcement noticed the alleged gunman, Thomas Matthew Crooks, before the rally began and designated him as suspicious. Local police alerted the Secret Service because of the man’s behavior near the magnetometers. Around 5:30 p.m. the shooter was spotted again looking through a rangefinder, a device shooters use to calculate distance to a target.

Those moments should have been enough to transform Crooks from a “person of interest” to an active threat. But that didn’t happen, and Cheatle deflected lawmakers’ questions with a bureaucratic defense. “I think we’re conflating the difference between the term ‘threat’ and ‘suspicious,’” she said. “An individual with a backpack is not a threat. … An individual with a range finder is not a threat.”

She was wrong about that. Instead of law enforcement questioning and searching him, the gunman continued his amateurish plan unmolested. About 10 minutes before Trump took the stage, Crooks had climbed atop a building a few hundred yards away with an unobstructed view of Trump’s podium.

The Secret Service has said the building where the shooter perched was outside its security perimeter for the event, but why? When Oversight Chairman James Comer (R., Ken.) asked about responsibility for the roof, Cheatle said there was “a plan in place to provide overwatch,” but didn’t provide details.

The Secret Service has acknowledged that its agents should have been in control of the building rather than relying on local law enforcement. This alone is a huge failure. Police provide additional security, but the Secret Service is the protection detail. Agents should be clearing all areas and keeping eyes on risky corners with drones or other surveillance.

In the minutes before he tried to kill Trump, the shooter was spotted by rally attendees who pointed and shouted to alert law enforcement. Why wasn’t the gunman taken out by snipers before he fired into the crowd. Why was Trump even allowed on stage?

Cheatle failed to answer those questions, telling lawmakers she needed to wait until the internal investigation is done in some 60 days, Her non-answers managed the rare feat of uniting Democrats and Republicans in calls for her resignation. Comer and ranking Democrat Jamie Raskin (D., Md.) both said she should go.

At the hearing, progressive Rep. Ro Khanna (D., Calif.) asked Cheatle if she knew what Secret Service director Stuart Knight did after the attempted assassination of Ronald Reagan. “He remained on duty,” Cheatle said. Khanna replied, “He resigned.”

Cheatle resigned Tuesday.