Scott Pruitt’s tenure as head of the Environmental Protection Agency is now deeply tainted by a stunning number of alleged ethical and legal violations. There are at least 12 investigations into potential violations like his luxury travel, his $3.5 million a year 20-person security detail, and his housing deal with a lobbyist’s wife.

Pruitt’s secret $43,000 phone booth has already been found to have broken the law. Newer details like Pruitt asking staffers to buy him a used Trump hotel mattress and to drive around to find Ritz-Carlton lotion have emerged. And fallout, like the resignations last week of two top aides, Millan Hupp and Sarah Greenwalt, continues.

To some Democrats in the House and Senate, environmental groups who’ve launched the Boot Pruitt campaign, and former top ethics officials, what should happen now is very clear: Pruitt should resign.

Mr. Pruitt, it’s simple: you break the law, we sues. Stop breaking the law and we will stop suing. Better still, just leave already. https://t.co/sqUIl3yJCw — Norm Eisen (@NormEisen) June 10, 2018

Yet in an administration afflicted with unprecedented turnover, Pruitt has remained startlingly resilient.

His subservience to Trump appears to be one reason why he has dodged the ax. “People are not people to [Trump], they are instruments of his ego,” Tony Schwartz, the ghostwriter on Trump’s book The Art of the Deal, told the New York Times. “And when they serve his ego, they survive, and when they don’t, they pass into the night.”

Pruitt regularly strokes Trump’s ego; recently he did so during the announcement of a revision of greenhouse gas rules for cars: “This president has shown tremendous courage to say to the American people that America is going to be put first,” Pruitt said.

And Maggie Haberman and Katie Rogers at the New York Times just reported that Trump uses Pruitt to vent about other cabinet members:

Among the president’s other confidants is Scott Pruitt, the administrator of the Environmental Protection Agency. Mr. Trump has dismissed the advice of several aides who have tried to persuade him to fire Mr. Pruitt in light of the growing questions about misuse of his authority. The two speak frequently, and the president enjoys discussing his negative view of Jeff Sessions, the attorney general, with the embattled E.P.A. leader.

But to understand why Pruitt endures, you also have to look at how he differs from three top Cabinet officials who were terminated: David Shulkin, Tom Price, and Rex Tillerson.

While palace intrigue and scandal played a role in their demise, in many cases there were substantive policy differences between the agency heads and the president, or, rightfully or wrongfully, the president blamed them for major policy defeats.

Pruitt, on the other hand, is the happy conductor of the Trump train. He has brought the White House most of the few policy successes it has to date. Deregulation is Trump’s mission, and by beginning the process of undoing rules like greenhouse gas limits, fuel economy standards, and pollution controls, Pruitt has proved himself to be one of Trump’s most effective subordinates.

Of course, prognosticating anyone’s future is a fool’s errand in the current administration, but looking at which Cabinet secretaries have been fired and why could provide a guide to Pruitt’s fortunes under Trump.

David Shulkin

Veterans Affairs Secretary David Shulkin, who was confirmed by the Senate by a unanimous vote last year, was fired by President Trump in March.

While he suffered his own high-priced travel scandal, the bigger issue was the loss of confidence from the White House and within his own agency, so much so that he posted an armed guard outside of his office.

The main friction point was that Shulkin resisted the Trump administration’s efforts to privatize the VA. And as he left his post, he openly defied the White House with an op-ed in the New York Times and a media blitz.

Rex Tillerson

As secretary of state, Rex Tillerson failed to build bridges within his own agency or find traction at the White House. He presided over a drastic reduction in career diplomats at the State Department and a precipitous drop in morale among the remainder, leaving damage that could last a generation.

But his inexperience with government was particularly crippling within the chaotic Trump administration, where he had to jockey for attention with former White House adviser Steve Bannon and the president’s son-in-law Jared Kushner, often finding his staffing and policy decisions overruled.

Tillerson’s frustration with the president was well known; he once referred to Trump in a meeting with national security officials as a “fucking moron.” Meanwhile, the president publicly rebuked Tillerson for his overtures to North Korea and later fired him, both via Twitter.

Tom Price

Probably the closest analog to Pruitt is Tom Price.

The former health and human services secretary stepped down last year after a series of reports that he spent more than $1 million on private air travel instead of flying commercial. He also had ethics problems and conflicts of interest that predated his time in office, including buying stock in pharmaceutical and medical device companies before voting on legislation that would affect them.

The problem was that Price didn’t have any big accomplishments that he could hold up in his defense. In fact, President Trump held Price personally responsible for the task of repealing Obamacare, a major campaign promise.

“Are you gonna get the votes? [Price] better get them,” Trump said at the Boy Scout Jamboree last year. “He better get them. Oh, he better, otherwise I’ll say, ‘Tom, you’re fired.’”

While Price did use his authority to weaken the health care law, Congress ultimately decided not to repeal it wholesale, and Price lost his job.

Pruitt has avoided these pitfalls, for now

It seems corruption scandals alone aren’t enough to get fired in the Trump administration, and Pruitt is hardly the most profligate spender. (Treasury Secretary Steven Mnuchin, who, like Price, spent more than $1 million on military and charter travel, still has a job too.)

And unlike Tillerson, Price, or Shulkin, Pruitt has helped Trump deliver on key promises in visible, if not tangible, ways. Pruitt is starting the process of rolling back regulations like greenhouse gas restrictions under the Clean Power Plan and the Obama-era Waters of the United States rule. That has made Trump very happy.

According to the Office of Information and Regulatory Affairs, the EPA launched 16 deregulatory actions in 2017, more than any other federal agency. Now, keen observers will note that “starting the process” is not the same thing as “repealing.” Indeed, rolling back regulations at the EPA is a long, tedious process.

But as I’ve noted before, these announcements have the effect of delaying the implementation of these rules, and stalling is a key part of Pruitt’s modus operandi. His allies are certainly aware that regulations could snap back in a future administration that isn’t so hostile to the EPA, or that courts could force Pruitt to act. Nonetheless, they’re happy to burn the clock, so even announcements of potential changes are points on the board.

“We are always interested in ways we can stop federal overreach and that is something that is so important to my constituents in Tennessee,” said Rep. Marsha Blackburn (R-TN) to Pruitt during one his hearings last April. “They’re very grateful that we had the delay in the WOTUS rule.”

Trump came to Pruitt’s defense again on Friday. “I’m not happy about certain things, but he’s done a fantastic job running the EPA, which is very overriding,” he said, according to E&E News.

Based on what we’ve seen, for Trump to fire Pruitt, it would take a serious defeat of a major policy initiative, it would require Pruitt to do a major 180 on Trump, or it would take a scandal even bigger than any other to date.

Meanwhile, he’s continuing to run up the score for Trump, most recently changing how the EPA measures costs and benefits to favor less regulation in various areas, including climate change. And again, there is always the possibility that Pruitt’s fortunes at the EPA will change suddenly, according to presidential whim.