My Craftsman leafblower does not start reliably. I have changed the spark plug and the gas filter, and the air filter was cleaned. I have opened the covers so I can see that the primer bulb is moving fuel, however, I do not see or smell gasoline on the spark plug. Should I?

You should see it on the spark plug.
Removed your carb , take it apart check your metering valve , make sure its opening the needle.
Check you inlet sceen make sure its clear.
Luck