I know she's 'one of us' and that's why people on FR are defending this, but it is clear to me that she was set up. Totally set up, and probably by a speech writer. She did not write the speech herself - no one does, even Obama had a speech writer. Thus, someone wrote the speech for her and decided to copy (yes, copy) parts from Michelle's speech. At the frequency that Presidential candidates operate at, there is no way Trump's team could have hired someone so amateur that they mistakenly copied a speech from a sitting First Lady. No way - no campaign could ever hire someone that juvenile/amateur. Which means one simple thing - it was done on purpose, and the Trump campaign has at least one speechwriter who decided to do that knowing the media frenzy it would generate. It was an embarrassment bomb thrown in.
It is my hope that the Trump campaign is screening its staff properly. What is (really) sad is that it is difficult to determine whether the saboteur is from the Democrats or from the Never Trump side.