Why is Pluto Associated With Power?

I was asked why I refer to Pluto as "power" and how this connects to its associations with evolution and transformation. 

First, addressing a sub-question - some astrologers apparently refer to Pluto as the Wound but that's not what I associate it with. I do see Pluto as a bringer of extreme change, sometimes trauma, death and rebirth. The change Pluto brings can hurt, but the wound that does not go away (the weakness, the vulnerability that must be dealt with) is Chiron. This is the Wound that remains and creates empathy and the ability to teach others. 

In my experience, at least. 

Pluto is about the deepest source of power you can uncover - the power that emerges after you confront being powerless. Before you can truly grasp Pluto's power you must go through the cycle of evolution- face your Shadow, your unconscious attempts to manipulate and conserve power (survival) as you deal with others and the inevitable failure as you realize you cannot control others. Maybe they control you. That's the powerlessness. 

And that's when you face your greatest fears and evolve to the point where you uncover the power that's not dependent on trying to control others or doing the repeat dance of being controlled/manipulated by someone who pushes your buttons. You tap into profound honesty and fearlessness and this leads to a natural ability to impact (magnetize and transform) others without manipulation and without being manipulated.

Essentially, you go through your own death and rebirth via the house and sign your natal Pluto is in. Or, via the house/sign that transiting Pluto is hitting (if it's making some notable aspects to your chart). Often, this can manifest as confrontations with people as they attempt to control or manipulate you. Or, perhaps what you consider to be essential (money, beauty, status, a relationship) is taken away (Pluto brings the metaphorical death). That's how you learn about your own relationship to power - when it's removed. 

What you resist is generally what you need to accept in order to evolve. And that's when you become aware of your true power. Remember that Pluto is associated with purging - you purge what's been keeping you stuck. 

This person also commented that Saturn was about control. Saturn controls via limits. Pluto controls by pushing past the limits - seeing how far you can take a situation, becoming obsessed with someone, all-or-nothing intimacy. Obsession (a Pluto vehicle for truly knowing someone on the deepest level) is about control. Staying stuck in the cycle of obsession or manipulation means you're not evolving and are, therefore, essentially powerless.

Natal Pluto is where your natural source of power lies and it's also where you'll encounter confrontations/deaths/rebirths. Transiting Pluto can be the external trigger that brings the same.