Twitter is buzzing like a chainsaw.
But nothing definite yet.
Spokesman says not an emergency:
https://www.bostonglobe.com/news/nation/2019/07/02/pence-unexpectedly-cancels-event/c70EzvMB7c94lxzLuidlWK/story.html?s_campaign=bostonglobe%3Asocialflow%3Atwitter