Thank you both for your responses. I edited the question with the "idiot" comment after I discovered what the problem was so wasn't really expecting to hear from anyone. In response to your comments, the plug wire was only just off of the plug, certainly not very far. Enough to see the spark. The sad story is that I removed the plug, walked down to the local hardware store to get a new plug. Took the old plug with me just to be safe. Found the matching plug, paid for it, stuck it in my pocket and walked home. Put in the plug with the same problem that existed before. After taking off the motor shroud, inspecting the wire and the gaps around the do-dad that generates the spark, washing all the accumulated crud out from the motor cooling fins and under the aforementioned do-dad and finding nothing obviously wrong, I stick my hand in my sweat shirt pocket, feel something and pull out the plug I had just purchased. I had reinstalled the original plug
. Put in the new one and I was mulching leaves 5 minutes later.
Nice thing about getting older is every day is a new adventure.