What does power in solidarity mean?

Solidarity refers to the unity (as of a group or class) that centers around common interests, objectives, standards, and sympathies. Historically, the term has most often been employed to refer to different wings of the same religion that move in common purpose or labor movements seeking to improve their bargaining position. Solidarity is also the name of the Polish Movement in the 1980s that sought to end Communism in Poland and was eventually successful.