Amy Walter and Tamara Keith on Warren’s poll numbers

Amy Walter of the Cook Political Report and NPR’s Tamara Keith join Judy Woodruff to discuss the week’s political news, including a new poll that shows Iowa voters favoring Sen. Elizabeth Warren, Sen. Cory Booker’s scramble to raise enough campaign money, and why a whistleblower complaint withheld from Congress may make some reluctant Democrats reconsider formal impeachment proceedings.