A not-so-subtle way to change the subject when you are about to be faced with being wrong about something. This is a reference to overlooking many many many problems with donald trump due to the single issue of Hillary Clinton's private email server, and using that reason as both a reason and defense for voting for him. This is currently used by trump voters any time any legitimate fault is found of Mr. trump.
Person A: "Mr. trump rants that the media inaccurately covers him but when a reporter is kindly attempting to get his point of view he not only refuses to give it, asking the reporter to figure it out on their own, then cuts off the interview. It seems his real issue with the media is that they WON"t lie for him."

Person B: "But her emails!"
by CLS 8888 May 9, 2017