Now my dishwasher is draining completely!
This is what I did: I lifted and pulled the lower spray arm (the propeller blade at the bottom of the DW, part#501 in the attached diagram), unscrewed the nut hub (the circular plastic piece beneath, part# 454), pulled out the fine filter (part# 451), pulled out the inlet cover (part# 506 in the second diagram), and cleaned inside the sump well over which the inlet cover was sitting. There I found all kinds of crap - thread, pieces of plastic packaging materials, pieces of steel wool from a scrubbing pad, etc. All this junk was clogging the drain!
See parts diagram
Second parts diagram
Hope this posting helps someone else!