Hillary was supposed to CRUSH Trump and landslide remember? A few weeks ago they werre talking about running up the score just to get a large mandate - now they are making excuses.
I think the biggest thing that happened other than complete ignorance of the Rust Belt was Comey's October Surprise. That really fucked up Hillary bad and being cleared of it 2 days before Election day was just classy.
But seriously, someone out there really didn't want her to win. Entire DNC emails hacked, Wikileaks, etc. Hillary could honestly make an argument that the election was rigged at her expense but at the end of the day, she has no-one to blame except herself.