just a sticky tumbler like mentioned. that button on your key is NOT for
releasing your steering wheel!!
to release your wheel when locked you just have to jerk the wheel to one side
or the other while turning the key! the button on your key is just for a
light that is built into the key

Well, the tumblers inside the lock were sticking (stuck). The graphite
will do a wonderful job of lubricating them but the WD-40 is going to
gum them up when mixed with the graphite. If you're lucky, it won't
happen and the moisture will actually carry the graphite into the
mechanism better. If it does gum up, you can flood the lock repeatedly
with electronics cleaner (dries with no residue) and that will clean
it all out. After letting it dry overnight, you can then graphite it
again. I've got one I hit with WD-40 years ago and it tried to stick
about a week later so I added a bit more graphite and all has been
well since...

The last few days I'd had to put some pressure to get the ignition key
to turn.  (I never knew the little button in the key is meant to be
pressed to release the lock when the steering wheel is turned to too
much of an angle when parked.)  Last night the key only turned a
little, then would get stuck and not go all the way, so I was unable to
start the car.  I put a lot of DW40 spray and dry graphite (still
sneezing and trying to clean off my hands) into the ignition keyhole
and waited a couple of hours, but it wouldn't work.  Then this morning,
after about a ten hour break, I went to the car again, and voila!  The
key works every single time.  The key comes back soaked with graphite
mixed with DW40 to a couple of inches.  Was this just a one-time
problem?  What is the nature of this problem?