What is the most likely explanation for the increase in federal spending?

The increase in federal spending is primarily driven by rising costs associated with mandatory programs such as Social Security, Medicare, and Medicaid, which are expanding due to an aging population. Additionally, discretionary spending has risen in response to economic challenges, including the COVID-19 pandemic, which prompted significant stimulus measures. Other factors include investments in infrastructure, climate initiatives, and national defense, all aimed at promoting economic recovery and growth.