Many people see power as essentially a negative - power-over - in that they understand it as both constraint and the opposite of individual freedom (liberty), with the latter being something they deeply value. This is in keeping with “classical liberalism,” that being a name for the individualist constitutionalist philosophy that deeply informs American liberalism and American conservatism. By this view, power over an individual is a bad thing except in those instances when it’s needed to limit power by protecting the freedom of another individual (or to protect their rights, meaning those all-important freedoms each person deserves as a person). This, then, is the dominant way of thinking in the United States, adhered to by many liberals and by many conservatives.
There is, however, even within this zone of thought plenty of room for disagreement. In part that is because people disagree about what counts as a constraint and therefore about exactly who (and what) has power over whom. Do employers have power over their employees even when those employees are legally free to quit any time they like? Do the economic structures we call “markets” exercise constraint over us all, or are they instead zones of freedom? Different answers to these questions lead to different (to many “red” and “blue”) views as to what forms of power (which unfreedoms) are necessary to protect freedoms, e.g., on whether or not there is a need for a minimum wage law.
Yet another way to think about power asserts that one ought not forget power-to, meaning the ability to get something done, to accomplish something. By this view, power is not necessarily a negative; power is not always at someone’s expense. Also according to this view (socialists in particular make this assertion) some forms of power-to are not only positive (because the thing that can be accomplished is good and fundamentally harms no one); they are also necessarily collective. In other words, says this point of view, there are some things that are worth doing (like implementing an efficient, useful transportation system) that have to be done together if they are to be done at all. Should we count such projects as liberty-creating or liberty-reducing forms? It depends on whom you ask.