With Josh Kraft officially kicking off his campaign to challenge incumbent Mayor Michelle Wu, battle lines are beginning to take shape in Boston's mayoral race.

Mayor Michelle Wu dismissed assertions from her newly announced opponent Josh Kraft that she’s a leader who “does not listen” and is disconnected from community concerns, while hitting back by portraying him as a carpetbagger.

NPR's Mary Louise Kelly talks with Boston mayor Michelle Wu, who just welcomed her third child. She's the first Boston mayor to give birth while in office.