10. Using the word "Killery."
9. Insisting that Hillary must stand down as a candidate for the nomination.
8. Saying that the Democratic primaries are rigged.
7. Insisting that in 2008, Barack trailed Hillary all the way until the last few primaries.
6. Saying that it was unfair that the media said Hillary was the nominee before New Jersey and California.
5. Campaigning for Jill Stein.
4. Saying that Hillary is not progressive.
3. Insisting, after mid-April, that Bernie still had a shot at the nomination.
2. E-mail and/or Benghazi.
And the number 1 reason I've blocked someone on Facebook: *drumroll*
1. Other related miscellaneous indications that they're low-information, non-math-doing idiots.