Attorney General William P. Barr appears before a Senate Appropriations subcommittee in April. (Andrew Harnik/AP)

When William P. Barr was nominated as attorney general, Never Trump Republicans and even some Democrats were strangely mollified. Despite his repeated criticisms of the Russia investigation and dalliances with anti-Clinton conspiracy theories, people seemed to believe he was at least a steady hand. How could the guy who rose to become U.S. attorney general for an institutionalist like George H.W. Bush, after all, really be a Trump guy?

As we have come to find out, there is a simple answer: He may not be a Trump guy, but the practical effect for Trump might be the same.

And now, one of his predecessors in the Bush administration is painting an ominous picture of what could lie ahead.

In a lengthy piece in the Atlantic, former deputy attorney general Donald Ayer suggests Barr is engaged in a planned assault on checks against presidential power. While Barr’s legal philosophy on this front has accrued to Trump’s benefit, Ayer says, it is not really about Trump, per se. Just as Vladimir Putin’s support for Trump was not really about Trump — but rather destabilizing the U.S. political system, a cause for which Trump was a readily available blunt instrument — Barr’s advocacy for pro-Trump causes may ultimately be about something besides helping Trump. In Ayer’s telling, it is about expanding the powers of the presidency, the bounds of which Trump is only so happy to test.

Ayer’s piece builds on some great reporting done recently by The Washington Post’s Tom Hamburger, who documented Barr’s long-held belief in the need for a powerful chief executive. And the fact that it is coming from a relatively understated former top Justice Department official in a Republican administration means it lands with some force.

That force is amplified in the conclusion. Here’s the last paragraph of Ayer’s piece:

Trump and his endless assertions of power offer countless opportunities to pick and choose those executive-power claims with the best chance to succeed in court. Thus, in the Trump administration, Barr may have found the ideal setting in which to pursue his life’s work of creating an all-powerful president and frustrating the Founders’ vision of a government of checks and balances. His strange pursuit of an investigation of the investigators — on the supposition that the FBI may have been improperly “spying” on the Trump campaign when they investigated Trump associates who were found to have met with various Russians — may be the opening public chapter in that endeavor.

However you feel about how Barr has conducted himself or his summary of the Mueller report’s principal conclusions on Russian interference in the 2016 election and possible links to the Trump campaign, Ayer is apparently hinting at something much darker. He seems to be suggesting that this investigation of the Russia investigation’s origins may in fact be some kind of retribution — or perhaps a warning against others trying to check the president’s power in the future.

That is connecting a dot or two, but it is not completely speculative. Barr has shown an interest in this in a way few Republicans, up to and including his predecessor Jeff Sessions and congressional Republicans, have.

Even before the Nunes memo came out, Barr suggested in 2017 there was a cause to investigate “various ‘national security’ activities carried out during the election.” He has embraced Trump’s “spying” rhetoric when it comes to FBI surveillance of former Trump campaign adviser Carter Page, even as FBI Director Christopher A. Wray and others have objected to that term. And in May, Barr leaned into that conspiracy theory, telling Fox News “there were some very strange developments” during the 2016 transition period. He said the answers he had gotten about the Page surveillance were “inadequate” and “not sufficient” and again called it “strange” that the FISA application referred to the Steele dossier.

As we have found out over the past year or so, this is fertile ground to be tilled when it comes to fomenting mistrust of the investigators. The FISA process is a messy and secretive one, about which people might be told things that, in context, are hardly surprising but can easily be made to sound nefarious and witch-hunt-y. The Nunes memo, for instance, noted that Democrats partially funded what became the Steele dossier and that this was not disclosed in the FISA application. What it did not tell you is that the FISA application acknowledged the political origins of the dossier, and any reasonable person would assume it came from Trump’s political opponents.

Put plainly, it is a situation rife with possibilities for misleading, and Barr is someone with a demonstrated history of doing just that. He has put a respected U.S. attorney, John Durham, in charge of his probe, but as with the Mueller report, Barr has plenty of authority to exercise over disclosure and other decisions. He is in a very powerful position here.

At least one former colleague is very concerned about where that might lead.