US President Donald Trump framed his sweeping rollback of federal climate change policy on Thursday as a political win over the Democratic Party's 'radical' environmental agenda, reprising a message Republicans have used in past elections and could turn to once again ahead of November's crucial midterms.

His announcement at the White House was one of the most significant moves of his second term in office. The president said he was revoking an Obama-era 'endangerment finding' from 2009 which held that pollution harms public health and the environment. For almost 17 years, the US has used that scientific finding as the legal basis to establish policies to reduce emissions from cars, power plants, and other sources of planet-warming gases.

This radical rule became the legal foundation for the Green New Scam, Trump said, using a term popular with Republicans for describing Democratic environmental and climate policies. The move marks the culmination of a decade-long push by Trump to tear up policies that Democrats and many climate experts say are needed to rein in emissions. It is one of the most far-reaching reversals of American climate policy yet.

Trump, who has called climate change a 'hoax' and a 'con job', dismissed the science underpinning the Obama-era rule in remarks that at times took on the air of a victory lap over his Democratic opponents. He focused on the economic impacts of reversing the endangerment finding, arguing that boosting fossil fuels instead of clean energy would lead to lower energy costs for American consumers. Trump also singled out the US auto industry as a major beneficiary of the change.

Lee Zeldin, the administrator of the US Environmental Protection Agency, made the announcement alongside the president and described the 2009 scientific ruling as the 'holy grail of climate change religion'. Both framed its revocation as an assault on overbearing federal regulations – part of a longtime message from Republicans that bureaucratic red tape is hindering economic growth.

This decision is 'the single largest act of deregulation in the history of the United States of America,' Zeldin said. The rollback sparked fury among Democrats and environmental groups who said it would wreck the US's ability to combat climate change. Trump reversed numerous Obama-era energy and environmental regulations in his first term in office and withdrew the US from the Paris climate accord, an agreement by countries around the world to lower emissions and address issues exacerbated by global warming.

In recent years, climate policy in the US has swung wildly depending on who is occupying the White House. However, the announcement on Thursday represented the largest move by Trump to dismantle the climate policies put in place by his Democratic predecessors.

Perhaps with this in mind, Trump took pains to argue that the move would save consumers thousands on new cars, a claim that many environmentalists are skeptical about. Trump and many Republicans have also asserted that Democrats' climate policies are extreme and out-of-touch with public sentiment.

As the midterm elections approach, the impact of Trump's climate rollbacks on voter sentiment remains uncertain, particularly as a growing percentage of Americans express concern over global warming according to various polls.