[quote=Dutchbag]
Also, I smell metagaming.
[/quote]

To be fair to him, from the Wikipedia article:

[quote]Although McKinley enjoyed meeting the public, Cortelyou was concerned with his security due to recent assassinations by anarchists in Europe, and twice tried to remove a public reception from the President’s rescheduled visit to the Exposition.[/quote]

There were already suspicions of a possible assassination attempt. What's to say the security isn't increased as a result?