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.

Mayor Michelle Wu will no doubt come up with some lame excuse for not testifying before Congress next month – maternity leave, racism, sexism, panic attack or some other equally bogus reason.