US Senate Democrats accused Elon Musk's social media platform X of providing preferential treatment to prediction market Polymarket, raising concerns about an unfair competitive advantage. In a joint letter disclosed by Semafor, Senators Catherine Cortez Masto (Nevada), Adam Schiff (California), Jacky Rosen (Nevada), and Richard Blumenthal (Connecticut) alleged that users reporting Polymarket ads through X's standard interface are unable to select a reporting option, while other ad types, including those from competitor Kalshi, function normally. The senators questioned whether this special treatment benefits US President Donald Trump and his family, noting that Donald Trump Jr. has invested in Polymarket and serves as an adviser to the platform. The letter included screenshots as evidence of the alleged disparity in ad reporting functionality.