Michele Bachmann, once a rising star of the Republican presidential field, is sinking into political oblivion.

The latest national poll, released Tuesday by CBS and the New York Times, shows the Minnesota congresswoman with just 2 percent of the vote, her lowest showing since April 1. Moreover, the candidate who won the Iowa straw poll in August is now in fifth place in the Hawkeye State and even further back in other early-primary states.