I Googled "josh shapiro trump rally asassination attempt" and could find no other sources for the story other than the Facebook post, so I reckon we'll have to wait and see if anything else pans out about it.
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“Trouble rather the tiger in his lair than the sage among his books. For to you kingdoms and their armies are things mighty and enduring, but to him they are but toys of the moment, to be overturned with the flick of a finger.”
― Gordon R. Dickson, Tactics of Mistake
― Gordon R. Dickson, Tactics of Mistake