He quickly rose within the ranks, as members elected him to be the local union's shop steward, treasurer, vice president, and then (in 1961) president.
In short workers were seeking gains through localized class struggle at the point of production where the institution of the elected and recallable shop steward was key.
For example, a shop steward and a member of parliament are in responsible positions; the former is responsible to the workers, the latter to the electorate.