Only 28 percent correctly said that about 4,000 Americans have died in the war, according to a survey by the nonpartisan Pew Research Center.
That's down from last August, when 54 percent gave the accurate casualty figure, which was about 3,500 dead at the time. In previous Pew surveys dating to 2004, about half have correctly given the rough figure for the approximate number of deaths at the time.
In the new poll, around a third said about 3,000 U.S. troops have died while about one in 10 said 2,000 deaths. Fewer overestimated the number of casualties: about a quarter put the figure close to 5,000.
Exit polls of voters in presidential primaries and many national surveys have shown the economy has displaced the war in recent weeks as the public's choice as the nation's top problem.
Iraq was the most avidly followed news story for most of the first half of 2007, but it has not been the most closely watched story in any week since mid-October, according to a Pew survey of people's interest in the news. The portion of news stories on the war has dropped in recent months as well, according to a study by the Project for Excellence in Journalism, a nonpartisan group that evaluates news coverage.
The Pew poll was conducted from Feb. 28-March 2 and involved telephone interviews with 1,003 adults. The margin of sampling error was plus or minus 3.5 percentage points.