“Now, the trend is get a killer one-word name, and the reason is that you can pivot into anything you want,” said Mr. Meystedt, who has traded domain names for years and owns Symbolics.com, which became the first public dot-com address when it was registered in 1985.

Even with years of experience, appraising the value of a domain name is difficult because their worth is so often determined by what a limited pool of buyers is willing to pay, he said.

That’s why Heritage Auctions said it had decided to sell Democracy.com in a sealed-bid auction, in which each potential buyer is blind to what others have offered. Unlike an open auction, in which the winner only has to bid slightly more than the second-highest bidder, sealed-bid auctions can pressure buyers to make offers closer to their own upper limits.

The foundations of Democracy.com

Democracy.com was registered in the mid-1990s by Intraactive, an online business in Washington, D.C., that claimed the name on behalf of the Democratic National Committee, according to a 1997 article in the magazine In These Times.

Back then, Intraactive was struggling to get rid of the domain, which the D.N.C. had never used, according to the article. But the business eventually found a buyer in John Carrieri, who said in an interview that his personal records indicated he had bought the domain name from Intraactive and that he believed the sale likely took place in or around 1998.

Mr. Carrieri, now the chief executive of an energy management business in San Diego, was an early investor in domains and once owned Jokes.com, which is now in the hands of Comedy Central, and Jobs.com, now owned by Monster. But while he ran those domains as businesses, he had more idealistic goals for Democracy.com.

“I wanted to spread democracy,” said Mr. Carrieri, who majored in history and political science in college and had planned to turn the domain into an educational resource.