The Pew Research Center found that 49 percent of respondents said the government could do more while 45 percent agreed. Sixty percent said measures adopted after the terrorist attacks of Sept. 11, 2001, have made the country safer and 35 percent said they have not.
The poll was conducted Thursday to Saturday, a few days after two bombs went off near the marathon finish line, killing three people and injuring more than 250.
Three-quarters (75 percent) of those polled said occasional terrorist actions are now a fact of life. That is up from 64 percent a year ago and statistically similar to the 74 percent who believed that in 2003.
A majority, 63 percent, said they followed news coverage of the bombings closely with 80 percent saying they followed it on television, 49 percent on mobile devices and 38 percent on radio. Only 29 percent said newspapers were a major source of information and 26 percent social networking sites.
The survey found only modest partisan differences with 69 percent of Republicans saying steps taken since 2001 have made the country safer, about 10 percentage points more than Democrats or independents.
Pew surveyed 1,002 adults by telephone. The margin of error was 3.7 percentage points for the entire sample.