They are trying to drive a wedge between Donald and Melania but they can't attack Melania outright because it will backfire horribly on them. So they are bringing up this birther (which itself is a Saul Alinsky tactic at shutting up Obama's critics) issue.
I am sure they will bring up the birthed issue on Harris when she announces her run
Bump. The left is so predictable. You’re right. That thought crossed my mind when I got to the birther part. Always ask why.