We often hear other advice, like: seek associates you are comfortable with, or who have things in common with you, or who can give you good advice. Or that you should focus on showing your value to your org as a whole. But these seem to me to be the usual fig leaf excuses. That is, these are things one can admit doing openly without violating the standard forager norms against overt coalition politics.
What smart folks probably really mean when they suggest that you get a mentor, is that you get a powerful ally. And while allies in high places can be especially valuable to you, to make it a win-win relation you are going to have to offer them a lot of value in return. You will even have to figure out how you can help them, and help them first; they don’t have the time, and don’t trust you yet. And when you succeed in finding such a powerful ally, you will submit and they will dominate. That doesn’t sound nearly as nice to say, however.
Hanson is responding to a thought-provoking and boldly-stated answer to the question, How do you start those relationships with potential sponsors you don't know well already? by Sylvia Ann Hewlett in discussing her book (Forget a Mentor) Find a Sponsor.