Political capital is an interesting topic because it doesn’t really exist in any sense of the words. Political capital is basically a possible future IOU. If you take care of people, they’ll take care of you. This is more commonly known as “doing the right thing” or “being a friend.”
Things do change slightly when you deal with leadership that you don’t encounter often. A favor at that level may get you a meeting you wouldn’t have gotten otherwise or allow you to table a suggestion and have it get real consideration. Political capital has value but it’s not an end to seek in itself.
That’s the secret to building real political capital – don’t try to collect political capital. As soon as people learn that you are only doing things that benefit you, they lose all sympathy to give you a favor back. You’ve already helped yourself.
The secret to all of this is to take care of people and ask for help when you need to. Give and get in equal measures. Treat everyone fairly. Don’t play unnecessary games and tell the truth. Not hard concepts but some people really struggle with them.
Karma is real.