Unemployment and Party Policies: There's a Correlation, But What's the Causation?

Can we conclude failed / succeeded party policies from the following chart? Or did the policies change too much from administration to administration even within parties to attribute this trend to a policy set typical of either party?

This being unemployment, down is good ... a reduction in unemployment. The chart starts with the first President whose full term is entirely within the standard BLS/FRED  "unrate" data. Figures are calculated by starting with the first full month of the administration and going to the first full month of the next administration or to the latest available month in the case of the current administration.

As a group since Eisenhower, Republican Presidents averaged a 2.05 point increase in unemployment per administration. Meanwhile Democrats averaged a 1.42 point reduction in unemployment per administration.

From all that I've seen beyond just this chart, I'm tempted to say that this chart illustrates the economic impact mainly of two things: Republican drives to cut spending to balance the budget and Democratic drives to strengthen the safety net resulting in more fuel to the consumer engine. However, I hesitate to state that as a definitive explanation at this point. It's more of a rough hypothesis.