Studies of the effect of media consumption on political beliefs have typically focused on the influence of news. Televised news has historically been one of the most popular genres of television. However, in an era of media choice, Americans can easily choose to avoid news programs. One of the few remaining media genres that still attracts a huge audience of Americans across the political spectrum is sports. My dissertation examines the effect of watching televised sports on politically-relevant beliefs. Specifically, I focus on two beliefs about competition: First, whether losses are legitimate, and second, whether group relationships tend to be competitive where one side can only gain at another side's expense. I first analyze the demographics of people who watch televised sports. I show that the audience for televised sports in the United States is extremely large, politically diverse, and politically engaged. In my first study, I examine how watching televised sports makes people better losers. I argue that sports have many ``legitimating rituals'' where competitors model acceptance of defeat, and such rituals promote acceptance of loss. I use a survey conducted shortly before and after the 2020 election to measure how Trump supporters reacted to his loss. I find that while Trump supporters considered the election to be less legitimate after Trump lost, the drop in perceived legitimacy was smaller among those who watched more sports. I then use a survey experiment to manipulate exposure to legitimating rituals, and find that viewing legitimating rituals in sports increases perceived legitimacy in an unrelated election. In my second study, I study how televised sports promote a zero-sum, winner-versus-loser view of group relationships. First, I use a survey to measure zero-sum thinking, and find that higher levels of watching team sports predicts greater zero-sum thinking. Next, I use a survey experiment to prime thinking about the winner-versus loser aspect of sports. I find that priming people to think about competition in sports increases their perceptions that other group relationships are competitive; for example, that trade agreements between countries must have a winner and a loser. I conclude by examining the difference between seeing politics as a sport versus seeing it as a war. I use an experiment manipulating the language used in news coverage to use words related to sports or words related to war. The use of words related to war increased perceptions that a politician was ideologically extreme, disrespectful to political opponents, and condoned violence. I further show that the proportion of words related to war has increased in cable news coverage of elections. My dissertation demonstrates that even ostensibly apolitical media can have a substantial influence on political beliefs. It shows that beliefs about political competition are influenced by watching sports, the most popular type of competition wo watch in contemporary America.