How do these two provisions help to explain why the national and state governments seem to be locked in a perpetual struggle for power?

The provisions of federalism and the Supremacy Clause contribute to the ongoing power struggle between national and state governments by delineating their respective authorities while also allowing for overlapping jurisdictions. Federalism establishes a system where both levels of government can exercise power, leading to competition over policy areas such as education, healthcare, and law enforcement. The Supremacy Clause asserts that federal law takes precedence over state law, often leading states to resist federal mandates to preserve their autonomy. This dynamic creates a continual tension as both levels strive to assert their influence and control over governance.