I read that headline in the New York Times. From the context, I understood that it means that Biden was a little too hasty. I would like to know the origins of this expression
When you want to ski fast like a downhill racer, you point your skis downhill and get over your skis, positioning your weight forward.
Similarly, when you ski jump, you get out over your skis to control your descent.
In either case, the connotation is that Vice-President Biden got to a position much more quickly than President Obama would have liked him to, before President Obama was quite ready to declare his position on the matter.
I am not sure if I was the originator of the phase but in a conversation 25 years or so ago with a coworker I was expressing the feeling I had of not being in control as a skier is when he is leaning too far forward and feels a lack of balance and control and knows he is about to lose all control and crash.
Now I again am not sure if others have used this expression before but since that conversation I and my friend/co-worker have used it repeatedly to convey the feeling of losing control. I believe we were the originators of that phase.