which factor affects congressional approval ratings the most?

While all the factors mentioned can influence congressional approval ratings to varying degrees, domestic events often have the most significant impact. This is primarily because domestic issues directly affect the daily lives of constituents, including economic conditions, healthcare, education, and public safety. When Congress takes action or is perceived as ineffective regarding these issues, it tends to resonate more clearly with the public and can lead to significant fluctuations in approval ratings.

Presidential actions and foreign events can also play a role, but the immediacy and personal relevance of domestic events typically make them a more powerful influencer of public opinion regarding Congress.