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.

Boston Mayor Michelle Wu has been asked to testify at a Congressional hearing as part of a federal investigation into sanctuary cities.

Boston Mayor Michelle Wu says her administration feels “very strongly that we’re on solid legal ground” in being a sanctuary city and is still reviewing a letter it received from Congress on getting called to testify on such policies.