Senator John Kyl and Representative West are lame ducks. Scott Brown is a lame duck. President Obama is not a lame duck.
The second and third definitions in Merriam Webster are relevant here.
2: an elected official or group continuing to hold political office during the period between the election and the inauguration of a successor3: one whose position or term of office will soon end
Since President Obama is neither of these, it is wrong to call him a lame duck and assume therefore has no power to act. He won’t reach lame duckness until after the 2016 election.
Here is Brian McFadden on lame ducks.
But we are in the midst of a lame duck session of Congress and we are trusting them to solve our fiscal crisis which they were unable to do the last two years. Good luck to us all!