[Mygirlsmom]

There will be a “national emergency” that will necessitate the enactment of martial law. El Gordito will find a way to get what he wants

Perhaps a mentally unstable guy who straps a fake bomb to his chest and demands to talk? If he can't round one up, I'm sure the Great Pansuit would be happy to lend hers.

[Army Air Corps]

I imagine that there will some kind of violence (a faked coup attempt or provoking an uprising in some part of the country) or he’ll “uncover a vast plot” and that will be the trigger for martial law.