American Airlines and Southwest Airlines announced on Tuesday that they would follow President Joe Biden’s executive order requiring that employees be vaccinated against COVID-19 by Dec. 8, defying Texas Gov. Greg Abbott’s executive order blocking mandates by any entity in the state. The companies, both based in Texas, argued that Biden’s mandate supersedes Abbott’s, which was issued on Oct. 11. The Republican governor said in a statement upon issuing his executive order (pdf) that the COVID-19 vaccine “should remain voluntary and never forced.” Southwest Airlines said in a statement that it “would be expected to comply with the President’s Order to remain compliant as a federal contractor.” American Airlines meanwhile said that although it was reviewing Abbott’s order, “this does not change anything” for the company. “We believe the federal vaccine mandate supersedes any conflicting state laws,” the carrier added. The carriers are among the state’s largest employers. U.S.-based employees …