lame duck

I was reading The Financial Times this morning and read this heading: "Obama - when the lame duck quacks".

How would you translate this heading into Spanish, taking into account that "lame duck" is a political term: http://en.wikipedia.org/wiki/Lame_duck_%28politics%2?

but its meaning is good or bad?

danield, a "lame duck" is a North American expression used to describe a President during the period of time between losing an election and the actual swearing in of the new President.

Thanks liudmilak and find information about it and I understood, I think with respect to the translation into Spanish would be more successful "pato rengo". Regards