In April 2018, "Politico" disputed the narrative that Pruitt had been effective in overturning Obama's environmental legacy. According to "Politico", "Pruitt has yet to create new regulations that would outlast his tenure or Trump's, or to rescind any of the regulations Obama created. He's only been able to delay a few that were already on hold before he took office because they were mired in litigation." "The New York Times" and "The Washington Post" noted that while Pruitt was prolific in undoing government regulations, legal experts said that Pruitt did so hastily and through poorly crafted legal arguments that lacked legal, scientific and technical data. As a result, legal experts considered it likely that some of the rollbacks may be reversed in the courts. Legal experts described the legal arguments made by Pruitt's EPA as unprecedented and a departure from previous Republican and Democratic administrations. Rutgers University professor Stuart Shapiro said that while Pruitt had weakened enforcement of existing regulations, he had not been successful at repealing regulations. By April 2018, six of Pruitt's rollbacks had been struck down by courts, and Pruitt had withdrawn two of his proposed rollbacks. Pruitt's legal document outlining the rationale to roll back a regulation on greenhouse emissions from vehicle tailpipes was 38 pages long, lacked the kind of data that courts expect in cases involving environmental regulations, and was mostly direct quotes from public comments made by automaker lobbyists. In contrast, the Obama administration's rationale for implementing the regulation in the first place was 1,217 pages long.