bridges in protest. Under heavy pressure from Texas business owners, who strongly criticized the "secondary inspections", Abbott canceled the policy on April 15. He said the reversal was because the governors of adjacent Mexican states had agreed to exercise stronger vigilance against human trafficking, drugs, and guns. Abbott's truck inspections ultimately cost Texas an estimated $4.2 billion and led to no apprehensions of drugs or illegal migrants. Environment , Abbott rejects the scientific consensus on climate change. He has said that the climate is changing, but does not accept the consensus that human activity is the main reason. In early 2014, Abbott participated in sessions held at the headquarters of the United States Chamber of Commerce to devise a legal strategy to dismantle climate change regulations. In 2016, he supported Scott Pruitt's appointment as head of the Environmental Protection Agency (EPA), saying, "He and I teamed up on many lawsuits against the EPA." As Texas attorney general, Abbott often sued the federal government over environmental regulations. After Joe Biden was elected president, Abbott vowed to pursue an aggressive legal strategy against the Biden administration's environmental regulations. Voting rights Abbott pressed for a purge of nearly 100,000 registered voters from Texas voter rolls. Texas officials initially claimed that the voters to be purged were not American citizens. The purge was canceled in April 2018 after voting rights groups challenged the purge, and officials at the Office of the Texas Secretary of State admitted that tens of thousands of legal voters (naturalized citizens) were wrongly flagged for removal. Abbott claimed that he played no role in the voter purge, but emails released in June 2019 showed that he was the driving force behind the effort. In September 2020, Abbott issued a proclamation that each Texas county could have only one location where voters could drop off early voting ballots. He justified the decision by claiming it would prevent "illegal voting" but cited no examples of voter fraud. Election security experts say voter fraud is extremely rare. Also in September 2020, Abbott extended the early voting period for that year's general election due to COVID-19; the Republican Party of Texas opposed his decision. Abbott made "election integrity" a legislative priority after President Trump's failed attempts to overturn the election results of 2020 United States presidential election by using baseless claims that the results were fraudulent. Voting rights advocates and civil rights groups denounced