In December 2020, McCarthy was one of 126 Republican members of the House of Representatives who signed an amicus brief in support of "Texas v. Pennsylvania", a lawsuit filed at the United States Supreme Court contesting the results of the 2020 presidential election, in which Joe Biden prevailed over incumbent Donald Trump. The Supreme Court declined to hear the case on the basis that Texas lacked standing under Article III of the Constitution to challenge the results of the election held by another state. In March 2021, McCarthy denied he had supported Trump’s false claims of election fraud, though he had supported "Texas v. Pennsylvania" that sought to overturn voting results in four states and voted in favor of a House resolution to overturn voting results in two states.