I spent another 40 minutes on the phone with GoDaddy with no solution. They had no advice for me except to tell me that a style sheet or template was missing even though I insisted I was looking right at them via FTP.
Then I noticed the redirect after again attempting to login to bidenizm.com/wp-login.php. It changed to bidenizm.com/bidenizm.com/wp-login.php. This appeared to be incorrect General Settings>WordPress Address & Site Address settings in WP admin.
Without dashboard access, I went into myadmin and changed the default wp_options>siteurl and wp_options>home values from http://bidenizm.com/bidenizm.com to just http://bidenizm.com/
The site works perfectly now, all because these values were somehow not preserved during the migration. I hope this helps someone else.