I listed mentors under the power player tactics, even though many neutrals can benefit from a mentor too. Why? Because only an aspiring power player can take full advantage of the mentor relationship.
Why would you want a mentor? There are four primary reasons.
First, a mentor is more senior in the organization, and generally already knows the lay of the land. Having access to a mentor immediately helps you better understand things like: what the organization values, and the existing political structure inside the company.
Second, mentors can teach you the skills in their toolboxes. If your mentor is an expert scapegoater, for instance, he or she can tell (and show) you how to use that tactic. If he or she is particularly good at setting credibly low goals and targets, you learn the tactic faster with active help from a mentor. Of course, you can learn all the tactics on your own -- through a combination of observation and trial and error, but having a journeyman there to counsel you makes it faster and much less risky.
Third, mentors will normally take your side. When you're searching for allies to push through approval on that controversial project, your mentor should be at the front of the line rallying help. And she might even tip you off that you're beating a dead horse, and should drop the effort altogether -- before you do some serious damage to yourself.
Fourth, mentors can be confidants. Remember when I discussed "keeping it to yourself", I said if you need someone to whine to about work -- get a dog? Well, the only possible exception to that rule would be your mentor, and even then only after the relationship has had a good period of time to season. Mentors generally will never throw their mentee under the bus. But if your mentor is an expert blame deflector or scapegoater, better to be cautious in this area. When it comes down to him or you, ninety five percent of the time, he's going to make sure its not him.
Picking a mentor can be tricky -- It's easy to outline the desirable characteristics: high up in the organization, politically adept in the same area of politics where you want to be yourself (a neutral for self-limiting neutrals, a street fighter for aspiring street fighters, etc.), a long term company survivor -- you don't want to develop your mentor relationship, only to have the mentor bail out for an opportunity at a different company. The tricky part is the personal chemistry involved. Normally, there is a mutual respect, or the mentor sees underdeveloped potential in the mentee. But you'll need to figure out the personal chemistry piece for yourself.
Which brings my last point -- why do senior managers become mentors? I can only offer a theory on this. I believe some managers have a strong need/desire to mentor younger employees from early in their careers. But I would guess they are the exception rather than the rule. Other senior managers seem to migrate to the mentoring role as they reach the apex of their careers. I believe it's a response to coming to grips with the end of their battle for the top position. Perhaps they see the next generation battle taking shape, and want to help favored candidates. Whatever the reason, those at their career summit do seem to make better targets for mentees to try to develop relationships with.
Which leaves me with a final observation on mentors -- do CEOs mentor? Or does the structure of their position, and their ongoing responsibility for managing succession in the company make it impossible, or at least unadvisable to become a mentor?