The measure for how “powerful” a passport is:

> The Henley Passport Index is the original, authoritative ranking of all the world’s passports according to the number of destinations their holders can access without a prior visa.

https://www.henleyglobal.com/passport-index

According to the article, the US passport was at the top of the list a decade ago, last year it was in seventh place, and now it’s in twelfth.