Environmental Protection Agency (EPA) Administrator Scott Pruitt. Saul Loeb | AFP | Getty Images

EPA Administrator Scott Pruitt reports to Capitol Hill on Thursday for a pair of hearings on his agency's 2019 budget proposal, but the embattled Trump deputy is likely to face as many questions about his personal conduct as EPA's spending priorities. Since the hearings were announced, revelations about Pruitt's rental of a Washington apartment linked to an energy lobbyist have sparked a near-daily trickle of reports detailing alleged ethics abuses and lavish spending that have put the EPA chief's political future in peril. In just the last few weeks, Pruitt has been accused of retaliating against EPA staff, arranging official trips to fulfill his personal travel whims and orchestrating pay raises for aides in defiance of the White House. The number of investigations into his conduct has expanded to five, and the government's top watchdog determined last week that the agency violated the law by installing a $43,000 soundproof phone booth in Pruitt's office. The hearings could be a make-or-break moment for Pruitt, who has already sat through a combative Fox News interview that reportedly bruised his standing in the administration. Pruitt goes before the House Committee on Energy and Commerce's subcommittee on Environment in the morning and the Committee on Appropriation's subcommittee on Interior, Environment and Related Agencies in the afternoon. The appearances present a rare opportunity for Democrats, who vilify Pruitt for leading President Donald Trump's efforts to roll back Obama-era environmental regulations and casting doubt on the scale of humanity's role in climate change.

Democrats on the House Committee on Energy and Commerce plan to use much of their time to grill the administrator on the recent accusations. "Again and again, Administrator Pruitt has abused his position for personal and political gain, including a sweetheart apartment rental from a lobbyist and a litany of wasteful taxpayer-funded indulgences in first-class flights, personal security, office and official vehicle upgrades, and massive raises for his political friends," said New York Democrat Rep. Paul Tonko, ranking member of the Environment subcommittee. "His subsequent denials and attempts to justify some of these ethics violations seem to have been complete fabrications," he told CNBC in an email. Tonko was among four Democratic Congress members who requested that Pruitt be put under oath during the testimony in a letter to Republicans, who hold the majority.

Republicans are the wild card

For Republicans, the hearings present something of a tightrope walk. The GOP rails against government waste but also views Pruitt as a key figure in Trump's deregulation agenda. Conservative lawmakers are also likely loathe to see the administration's reputation sullied by another spending scandal ahead of midterm elections. The White House may have made that balancing act less perilous. It has reportedly instructed conservatives not to defend Pruitt too stridently. Just five House Republicans have joined 170 Democrats in calling on Pruitt to step down, but there are other signs that GOP support is eroding for the EPA chief. Three Senate Republicans on Monday called for hearings on Pruitt's conduct. Trump has oscillated between non-committal statements — at one point saying, "I hope he's going to be great" — to an adamant defense of Pruitt on Twitter. @realDonaldTrump: While Security spending was somewhat more than his predecessor, Scott Pruitt has received death threats because of his bold actions at EPA. Record clean Air & Water while saving USA Billions of Dollars. Rent was about market rate, travel expenses OK. Scott is doing a great job! Still, the White House is leading its own investigation into Pruitt. Another probe has been opened by Trey Gowdy, the Republican chair of the House Oversight Committee. On Monday, Democratic lawmakers sent new evidence to Gowdy showing the head of Pruitt's security tapped a business associate to conduct a security sweep of Pruitt's office, which was found by an internal review to have been "very basic and cursory" and inadequate to clear the office for discussing or transmitting classified information.

Mounting ethics questions

Questions about EPA spending under Pruitt date back to last fall and resurfaced this winter, but have gained seemingly unstoppable momentum in recent weeks. At the heart of the investigations is whether Pruitt violated federal rules by renting a Capitol Hill condo owned by the wife of prominent energy lobbyist Steven Hart. An EPA watchdog initially determined the arrangement did not violate federal gift-giving rules, but he later clarified that he did not have enough information to clear Pruitt of wrong-doing. This past weekend, Politico revealed Hart and Pruitt met in an official capacity while Pruitt was still occupying the apartment, despite their earlier assertions to the contrary. Hart's firm, Williams & Jensen, also had business before the EPA. Pruitt's claim in the Fox News interview that he did not know who went behind the White House's back to approve pay hikes for two of his long-time aides is also contested. EPA chief of staff Ryan Jackson has since taken responsibility, but Republican whistleblower Kevin Chmielewski told lawmakers the decision was "100% Pruitt himself." Chmielewski, a former Trump campaign staffer, is one of several EPA employees Pruitt allegedly pushed out for challenging his spending habits. Multiple investigations are looking into expenses accrued by Pruitt for first-class flights, trips home to Oklahoma and his unusually large private security detail.

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