Thanks for all the good ideas. In the mean time I called a local
mechanic. He said the battery had gotten bad enough that it could not
turn over the starter even though it could pass on enough electricity
to operate the lights, radio, etc. I tested 12 volts with my volt
meter. The guy I talked to said I needed a load reader in order to
test the battery correctly, that my volt meter wasn't good enough.
Because the battery was bad (couldn't generate enough load), I couldn't
even jump it (as the battery needs to be good to jump a car because the
jumper juice goes through the old battery?). I followed his advise and
got a new battery and the car started right up.