“They’re a small, select group,” said Peter Brown, assistant director of the Quinnipiac University Poll, who had nothing to say about them beyond that. They showed up in polls this month from Fox News and George Washington University, but the Pew Research Center was also at a loss to explain them. “The group is too small to break out and analyze,” wrote a Pew spokeswoman.

It’s possible they’re more myth than reality. “The error factor’s 3.2 percent. So they may exist. They may not exist,” said Republican pollster Ed Goas, who co-conducted the May GWU poll. For comparison, about 1 percent of respondents in that poll were also “unsure” of their own age or refused to divulge it. “There’s a certain number of people who go through life clueless,” he said.

“Quite frankly, it’s not a big enough group to look at,” said Goas, who nonetheless was game to glance at the poll’s cross tabs — the demographic breakdowns of every answer to every question — and take a few guesses. The “never heard of” responses tick up slightly among ticket splitters, voters in Florida and those who believe “retirement” is the economic issue the next president should focus on. “My sense is that this is older voters who quite frankly are very apolitical,” said Goas, though he cautioned, because of the miniscule sample size, “You just can’t draw any conclusions.”