When Warren Harding called for a return to normalcy, what did he mean?

For Harding, a return to normalcy meant the end of the progressive and internationalist ideals championed by his predecessor, Woodrow Wilson. Harding wanted the United States to stay out of European affairs altogether—Harding knew nothing about foreign affairs and his campaign handlers endeavored to keep him out of that realm. Harding stayed true to the Republican party line of the time by not supporting the League of Nations. Harding also wanted to restore the business practices of the Gilded Age where business was able to do whatever it wanted without governmental involvement. Harding allowed oil interests to dig in public lands. He also cut taxes on business.
Harding would have been quite at home in the Gilded Age. He wanted his presidency to be forgettable. He even waged a "front porch" campaign where his campaign managers did most of the work and Harding made few public appearances. Harding's presidency was known more for personal and public scandal than it was anything positive.