So many different scandals have engulfed Scott Pruitt, head of the Environmental Protection Agency (EPA), that multiple publications have created trackers to help readers sort them out. Pruitt’s excessive spending and his fraternization with lobbyists and controversial figures may eventually force him to step down. But the focus on his flawed personal ethics risks obscuring his broader mission: the dismantling of his own agency.

That effort relies on tactics deployed by two previous Republican presidents — Ronald Reagan, who staged a frontal assault on the EPA early in his presidency, and George W. Bush, who worked to undermine the science underpinning the EPA’s actions — and constitutes an all-out war on the agency. Yet it is not clear whether Pruitt’s departure would alter this trajectory, or whether the Trump administration will continue down this path, inflicting irreparable damage on one of our most important governmental agencies.

Back in 1980, Reagan galloped into office with a campaign that, like Trump’s, decried government “overreach.” Once in office, Reagan selected an EPA head hostile to the agency’s initiatives: Anne Gorsuch (mother of Supreme Court Justice Neil M. Gorsuch). As a corporate lawyer and Colorado lawmaker, Gorsuch had opposed the Clean Air Act, water quality rules and hazardous waste protections. Other EPA appointees came from regulated industries and companies, including Exxon and Aerojet.

Once in office, Gorsuch shrank EPA staff levels by 21 percent between 1981 and 1983, slashed the agency’s budget and dissolved its Office of Enforcement. In the first year of the new administration, civil enforcement cases plummeted by about 75 percent.

Gorsuch’s assault on the EPA was ultimately cut short. EPA career staff gathered in bars to plot strategies of resistance and unionized themselves to promote job security and scientific integrity. Leaks from the agency and subsequent headlines led the Democratic-controlled House of Representatives to launch investigations. Major corruption and misconduct were uncovered in the Superfund cleanup program, with its head, Rita Lavelle (plucked from Aerojet), jailed for perjury.

When Gorsuch shrugged off a congressional subpoena, 55 House Republicans joined Democrats to charge her with contempt. The White House turned against her, driving Gorsuch and a score of other political appointees out. Reagan then appointed William Ruckelshaus, the EPA’s first administrator and a strong advocate of its mission, to lead the agency. Ruckelshaus helped revitalize staff morale and bipartisan support for the EPA.

After Gorsuch’s ouster, the Republican siege of the EPA abated for 17 years. In fact, Reagan’s successor, President George H.W. Bush, appointed the “first professional environmentalist,” William Reilly, to lead the EPA and signed the United Nations Framework Convention on Climate Change, acknowledging the human role in climate disruption. But Bush’s son, President George W. Bush, resumed the charge, in a more sophisticated and less overtly confrontational manner than Reagan.

Bush’s first EPA administrator, former New Jersey governor Christie Whitman, was more in the mold of Ruckelshaus and Reilly. Nonetheless, more systematically than ever before, Bush and Vice President Richard B. Cheney nurtured a political climate that challenged the science undergirding EPA actions. Climate change science was the biggest victim. Political appointees required reports to include language about the uncertainty of climate change, and EPA employees were prohibited from discussing the topic.

These moves gave Bush, Cheney and their allies the cover to withdraw from the Kyoto Protocol talks, promote fossil fuel development, exempt fracking from the Safe Drinking Water Act and downplay renewable energy and energy conservation. In response to being incessantly undermined by Cheney, a frustrated Whitman eventually quit.

These past attacks have done damage to our environment and climate. But the EPA survived and has even been able to adapt its regulations to new science, despite ongoing industry pressure and relatively stagnant budgets. It now faces a historically unparalleled threat.

Trump and Pruitt have combined the overt attacks pioneered by Reagan and Gorsuch to the more sophisticated Bush strategy of corroding the science driving the EPA’s activities.

Like Reagan’s team, Trump’s top EPA appointees, Pruitt and Andrew Wheeler, built their careers fighting the EPA, as Oklahoma’s attorney general and a coal company lawyer, respectively. Lower-level appointments are exemplified by Nancy Beck, who is leveraging years of experience as an industry lobbyist to rewrite chemical safety rules.

Similarly, Pruitt has reduced EPA staff levels to numbers not seen since Reagan. Thanks to voluntary buyouts and a hostile work environment, more than 700 employees have left the agency and another 2,000 positions are vulnerable. The consequences for EPA enforcement were evident after Trump’s first nine months in office: It filed one-third fewer civil cases against polluters than under Barack Obama and a quarter fewer than under George W. Bush.

Like Bush, Trump and Pruitt’s team has controlled and manipulated EPA science. Climate change information has been scrubbed from websites. The administration dismissed many academics on scientific advisory committees, allowing — for the first time — lobbyists to sit on these boards. Pruitt is also trying to limit the ability of the EPA to rely on the studies that justify pollution controls.

These efforts to silence science are more significant, more ambitious and more overt than those undertaken by Pruitt’s predecessors.

Most significantly, Pruitt’s efforts enjoy unprecedented support from the White House. Trump, who campaigned on reducing the EPA to “little bits,” issued a flurry of executive orders to undermine existing environmental protections in his first weeks in office that exceeded both Reagan’s and Bush’s in their number and scope. As a veteran from the Reagan years reflected, by the time Trump’s administration is done slicing, the EPA will be “a much smaller and probably much more passive operation than what you’ve got now.”

Just as under Reagan, EPA career staffs are fighting back, leaking damaging information to the media. While leaks and bad news coverage were preconditions for toppling Gorsuch, they are unlikely to trigger similar corrective action from a president and a party that has increasingly embraced anti-environmentalism.

Part of the tide turning on Gorsuch was Republicans abandoning her. But that hasn’t happened to Pruitt. He recently fielded softball questions from congressional Republicans during a hearing on Capitol Hill. Indeed, congressional Republicans continue to laud his efforts to undo Obama-era regulations. They are bolstered by an array of highly conservative media voices — something that did not exist in the early 1980s — who praise Pruitt’s attacks on the agency.

Even if Pruitt gets pushed out, Trump’s continued strong support for his actions indicates his replacement is likely to be someone equally committed to Trump’s vision of a dramatically smaller, less effective EPA.

There are some checks that will limit this project. Democrats, with support from some Republicans, provided insulation against the deep EPA budget cuts proposed by Trump. If Democrats gain control of the House in November, they will probably go on the offensive, trying to undermine these efforts through investigations and the power of the purse.

At the state level,  attorneys general are already suing Pruitt’s EPA for failing to expand ozone regulations and for walking back fuel efficiency standards. Many are adopting stronger state regulations on issues from climate change to regulating toxic substances.

In the absence of federal leadership, however, state initiatives are crucial but insufficient. The EPA was created to address an uneven, and often ineffective, patchwork of state laws. While Pruitt’s fate may be uncertain, his ouster would not undo the damage that he is inflicting on the EPA unless his initiatives are also reversed. This means reviving its budget and staff numbers, restoring the agency’s reliance on science and ridding its hallways of those whose industry ties deeply compromise their decisions and judgments.

The research underlying this article comes from the Environmental Data & Governance Initiative (EDGI), an organization addressing threats to federal environmental policy and data.