It takes place November 3 on the National Mall in DC.
Michael Bellavia, 43, an animation executive from Los Angeles, and Chris Mecham, 46, a university student in Idaho, separately came up with the Million Muppet March idea in response.
Big Bird, played by actor Carroll Spinney in an 8-foot (2.5-metre) bird costume, is strictly speaking not a member of the group of puppet characters known as the Muppets.
Bellavia bought the Internet address www.millionmuppetmarch.com during the debate and discovered Mecham had already started a Facebook page by the same name.
Within 30 minutes of the end of the debate they were on the phone with each other, planning the march.