Bloomberg's John Heilemann said Hillary Clinton should be worried that Sen. Bernie Sanders (I., Vt.) is drawing enormous crowds on Thursday’s With All Due Respect.
On Wednesday, Sanders was in Madison, Wis., and drew a crowd close to 10,000 people.
"Hillary Clinton should still be concerned about the fact that someone else in the Democratic party is drawing 15,000 people or 10,000 people and it's not her," Heilemann said.
Recent polls show that a growing number of Democrats are feeling the Bern.