GROUPS -- Age is a significant factor in views of the country's greatness. Eighty-three percent of adults 50 and up call the United States the greatest country in the world; that drops to 68 percent of those under 50. (It's 74 percent among people in their 40s, 69 percent among those in their 30s and 61 percent among 18- to 29-year-olds. These differences by decade, though, don't reach statistical significance, given the sample sizes.)
Under-30s, moreover, are more apt than their elders to be pessimistic about the system and how well it works, 28 percent compared with 18 percent.
There's an income gap as well, perhaps reflecting differences between those who have and haven't achieved relative prosperity. The share of people who call America the greatest country ranges from 85 percent of those with household incomes higher than $75,000 to 71 percent of those with annual incomes less than $25,000.
There aren't significant partisan differences in views of the country's greatness -- three-quarters of Democrats and independents alike, and eight in 10 Republicans, call the United States the world's greatest country. But optimism about the system and how it works is higher among Democrats than it is among Republicans and independents. And, perhaps helped by the presence of the first African-American president, pessimism is notably low among blacks (5 percent compared with 22 percent among whites).
Optimism about the system, naturally, is higher (39 percent) among people who believe America still is the greatest nation than it is among those who believe it's no longer the greatest (14 percent optimistic). (Perhaps reflecting reflexive national pride, the question, originated by NBC News in 1984, doesn't include an option of saying the country never was the world's greatest -- only that it still is, or used to be but isn't now.)
Finally, partisan differences are sharpest on the question of what's to blame for problems in the way the system of government is working -- the system, or the people running it. About two-thirds of Democrats and independents say it's the people. But this jumps to 90 percent of Republicans -- the ones who, as previous polling has shown, are most dissatisfied with the way the government's operating now, and the most eager to change it in next week's election.
METHODOLOGY -- This ABC News/Yahoo News poll was conducted Oct. 13-20, 2010, among a random national sample of 1,025 adults. Respondents were selected using an address-based sample design. Households for which a phone number could be ascertained were contacted by phone; others were contacted by mail and asked to complete the survey via a toll-free inbound phone number or the Internet. See details here. Results for the full sample have a 4-point error margin. Click here for a detailed description of sampling error.
This survey was produced by Langer Research Associates of New York, N.Y, with sampling, data collection and tabulation by SSRS of Media, Pa.
ABC News polls can be found at ABCNEWS.com at http://abcnews.com/pollingunit