Final answer:
The Korean War affected politics within the United States by contributing to the rise of McCarthyism, increasing support for military intervention, and undermining support for social welfare programs.
Step-by-step explanation:
The Korean War had a significant impact on politics within the United States. First, it contributed to the rise of McCarthyism as Americans looked to assign blame for the stalemate that ended the war. The fear of communism grew, leading to investigations and accusations of communist sympathizers in the government and entertainment industry. Second, the war increased support for military intervention to support containment, as South Korea had been protected from communism. This further solidified the Cold War mentality and the belief in the need to combat the spread of communism. Lastly, the war did not result in a decisive victory and led to frustration among Americans, which undermined support for social welfare programs as more funds were demanded to support the war effort.