Dr. Jeffrey Pfeffer of Stanford University recently wrote Power: Why Some People Have It - And Other Don't and was recently published in HBR.
In a nutshell, he says that leaders who do as they please and allow their whims to overtake company practices and rules may have more power ("Wow, he can do what he wants, he must be important") but that power may not be good for the organization, or get the executive what he really wants. It is a combination of high ego and low self control.
"And what of the people who are subject to the whims of bosses behaving in unpredictable ways?" Dr. Pfeffer asks. "They pay a huge price. Motivation declines...learning suffers...and stress skyrockets."
How about instead having a healthy ego and high EQ? Now that's power.