My bad. I didn't remove the database. I had assumed it was in the app directory.
When I deleted everything of the form ~/Library/Containers/com.evernote.*, Evernote started to work again.
Thanks so much!
Recently did some software updates on my Mac, and Evernote no longer opens up. I have the latest versions of everything. I uninstalled and reinstalled Evernote. Any ideas how to fix this? The few forum topics I saw the problems just resolved itself.