Hell they probably would have accepted the offer for a free pen test. Instead many orgs react rather violently if they dont know about it and you did it.
An unexpected, unauthorized, "free pen test" is indistinguishable from a bad-guy cracking attempt, and must be treated as if it's a real threat. This causes ENORMOUS extra costs as the victim has to batten the hatches, examine everything for corruption and/or possible persistent threat instalation, compare working databases to backups and examine the differences vs. update audit trails, and so on.
Not to mention the concern that it might be a real attempt by the DHS, or a rogue group within it, to hack the election.