CNN  — 

Don McGahn’s name hasn’t been in the news much of late. But a judge’s ruling Monday that the former Trump White House general counsel cannot resist a subpoena to testify from Congress in its ongoing impeachment hearings has wide-ranging implications for a number of senior administration officials tied to the Ukraine probe.

“However busy or essential a presidential aide might be, and whatever their proximity to sensitive domestic and national-security projects, the President does not have the power to excuse him or her from taking an action that the law requires,” Judge Ketanji Brown Jackson wrote in her opinion, adding: “Stated simply, the primary takeaway from the past 250 years of recorded American history is that Presidents are not kings.”

That ruling is in the process of being appealed and could well end up before the Supreme Court. But in affirming the findings of lower courts, what Jackson did is send a clear signal that executive privilege cannot be claimed overly broadly to keep aides and former aides to speak about potential wrongdoing that they either witnessed or were a part of.

It’s in keeping with the argument put forward over the weekend by House Intelligence Committee Chairman Adam Schiff (California) regarding decisions by McGahn as well as acting White House chief of staff Mick Mulvaney and Trump personal attorney Rudy Giuliani to resist House subpoenas to testify on Ukraine.

“Because we have adduced so much evidence of guilt of this President, so much evidence of serious misconduct, any privilege the President would have would be vitiated by this crime-fraud exception,” Schiff told CNN’s Jake Tapper.

While Trump allies insist that this fight is far from finished – and they’re right – it’s important to understand the psychological (not to mention the legal) impact of this decision on those members of the Trump administration who have continued to refuse to testify.

Obviously, if you are McGahn, you have to now prepare yourself for at least the possibility that you will be asked – under oath – about your role in the potential obstruction of justice by Trump in Robert Mueller’s special counsel probe into Russian obstruction in the 2016 election. (McGahn is requesting a week-long stay so he can appeal the ruling.)

But if you are, say Guiliani or Mulvaney, this ruling has to give you pause. Yes, McGahn is a former White House employee while Mulvaney and Giuliani currently work for Trump. (Former national security adviser John Bolton, it’s worth noting, is also a former administration official who has not been subpoenaed, but who House investigators *really* want to talk to.)

Giuliani and Mulvaney could possibly hang their hats on the idea that Trump’s broad claim of executive privilege could well apply to them as active employees in a way that courts have ruled it doesn’t apply to McGahn. Maybe! But that line of reasoning took a hit on Monday – and will force anyone with an outstanding subpoena from Congress to reconsider their position at least somewhat in the coming days.

“I would actually like people to testify,” Trump tweeted Tuesday morning. “Don McGahn’s respected lawyer has already stated that I did nothing wrong.” Added Trump: “I would love to have Mike Pompeo, Rick Perry, Mick Mulvaney and many others testify about the phony Impeachment Hoax. “

One other ripple from the McGahn decision is this: Schiff now faces a tougher choice in whether to wait out some of these bigger-fish witnesses or move the impeachment process to the Judiciary Committee for the presumed writing of articles of impeachment against Trump.

“Yes, we’d love to have these witnesses come in, but we’re not willing to simply allow them to wait us out to stall this proceeding, when the facts are already overwhelming,” Schiff told Tapper on Sunday. “We’re going to continue our investigation. We are going to continue to pursue the documents.”

Monday’s ruling seemingly speeds up the timeline on the so-called “stalling” considerably. If McGahn is compelled to testify, there’s a precedent that would make it very difficult for Bolton to avoid testifying. And if McGahn and Bolton testify, suddenly the possibility of Mulvaney or even Giuliani testifying seems a whole lot more real.