The original Unions seemed much more about workers than political power.
Yup.
Very few worker rights . . . long hours, no overtime . . . no child labor laws or worker safety rules. Anyone could be fired at will (not to be confused with RTW states now). No pension, no health insurance.
By the 1950's or so they really outlived their usefulness because of labor laws. Also some bad apples (Hoffa), stealing from the pension fund, etc. prevalent in the 60's and later.
This article about Gompers and the AFL is revealing.
Samuel Gompers | AFL-CIO
aflcio.org