Losing Your Bearings

So Obama says McCain is losing his bearings because McCain suggested that an Obama victory would be good news to Hamas. (You can see the full CNN interview here.)

And a McCain aide fires back that this was a hypocrical, ageist remark.
You can read about that here.

My question is:
What's a bearing, and what have you lost when you've lost yours?
I looked up "bearings" and found two meanings:

• in navigation, the direction one object is from another object, especially the direction of an object from one's own vessel.

• in mechanics, a device to permit constrained relative motion between two parts, typically rotation or linear movement.

If bearings is thought of in the mechanical sense, "losing your bearings" reminds me of losing ball bearings, which seems like "losing your marbles," which sometimes happens to people when they get old. It certainly would be quite an insult, and perhaps ageist, to say of an elderly political candidate that he has lost his marbles.

If bearings is thought of in the navigational sense, as it traditionally has been, in expressions such as "get your bearings," "find your bearings," and of course, "lose your bearings," then to say someone has lost his bearings is to say that he has lost his sense of his position relative to other people's positions.

So, if you were to implicitly criticize some one's political position, and it turns out that he holds the same political position as you do, it would be fair to say that you have lost your bearings. You're talking as if someone is a great distance from you, when actually he's at the same place as you are on this issue. Incidentally, in the next sentence after the "losing his bearings" remark, Obama stated that he and McCain have the same stance with respect to Hamas.

To say that someone has lost their sense of the political landscape is not an especially ageist remark as far as I know. So, it doesn't strike me as a "not particularly clever way" to raise the issue of age, since it's not a way to raise the issue of age at all.

...unless Obama was hoping we would be confused between ball bearings and relative position, as Leiberman seemed to be.