"I’m sure someone will jump in," the Minnesota Democrat said.
Activists argue Democrats played it safe, sidelined the president and lost in 2014.
The Florida GOP senator is making all the moves of a potential presidential candidate.
Biden reportedly said income in the U.S. is the most unequal it has been since 1920s.
They found common ground on foreign policy, war on drugs and prison sentencing reform.
Laura Barron-Lopez 11/14/14 05:20 PM EST
House Dems are furious their Senate colleagues have hijacked Keystone to save Landrieu.
An earlier report claimed Dems had narrowed finalists to Brooklyn, Columbus and Philadelphia.
The White House adviser said he will "do whatever she asks me to do."
Chicago Sun-Times reports Ill. Dem is thinking of challenging Sen. Mark Kirk (R).