Elon Musk’s polarizing political actions since acquiring Twitter, later rebranded X, in 2022 dramatically hurt the automaker’s U.S. sales, underscoring how deeply its fortunes are intertwined with the billionaire’s persona.

The findings quantify for the first time how the political actions of the world’s wealthiest person – including his role in U.S. President Donald Trump’s administration – may have cost Tesla billions in lost vehicle sales while benefiting rival electric carmakers.

Tesla’s U.S. sales would have been between 67% and 83% higher, or about 1 million to 1.26 million additional vehicles, from October 2022 to April 2025, had it not been for what researchers call the “Musk partisan effect,” according to a working paper from the National Bureau of Economic Research by Yale University economists.