meaning - Is there a difference between "political science" and "political sciences"?

I am doing a research about research disciplines. I found it confusing and surprising that there are two ways to refer to "political science(s)"

Google:

1. "political science" returns 26 million results.


2. "political sciences" returns 4 million results.

It seems like a considerable amount of texts refers to what I understand as "sciences". Does it mean that there are many sciences?