A new Quinnipiac poll has found a significant shift in public opinion on the trade-off between civil liberties and national security. In the new survey, released on Wednesday, 45 percent of the public said they thought the government’s antiterrorism policies have “gone too far in restricting the average person’s civil liberties” — as compared with 40 percent who said they have “not gone far enough to adequately protect the country.”

By comparison, in a January 2010 Quinnipiac poll that posed the same question, only 25 percent of the public said the government had gone too far in restricting civil liberties, while 63 percent said it hadn’t gone far enough to protect the country.

Although the shift in opinion is apparent among virtually all demographic groups, it has been somewhat more pronounced among Republicans, who may be growing more skeptical about President Obama’s national security policies. Whereas, in the 2010 survey, 17 percent of Republicans said the government had gone too far to restrict civil liberties while 72 percent said it had not gone far enough to protect the country, the numbers among G.O.P. voters were nearly even in the new poll, with 41 percent saying that antiterrorism programs had gone too far and 46 percent saying they haven’t gone far enough.

We generally caution against reading too much into a single poll result. But there are several reasons to think that the shift detected by the Quinnipiac poll is meaningful. First, the magnitude of the change was considerably larger than the margin of error in the poll. Second, the poll applied exactly the same question wording in both 2010 and 2013, making a direct comparison more reliable. Third, this was a well-constructed survey question, describing both the benefit (protecting the country) and the cost (restricting civil liberties) of antiterrorism programs in a balanced way.

What is less clear how much of the shift was triggered by the recent disclosures about the National Security Administration’s domestic surveillance programs, as opposed to reflecting a longer-term trend in public opinion. A Fox News poll conducted in April, just after the Boston Marathon bombings but before the N.S.A. story broke, found that only 43 percent of the public was “willing to give up some of your personal freedom in order to reduce the threat of terrorism” — considerably lower than in other instances of the survey. However, Fox News had last posed this question in 2006. Either way, it seems safe to conclude that the climate of public opinion on this issue has changed considerably since the years closely following the Sept. 11 attacks.

The Quinnipiac poll also asked about Edward J. Snowden, the former N.S.A. contractor who disclosed details about the agency’s programs to newspapers. The Quinnipiac poll, in contrast to other recent surveys, found ostensibly sympathetic views toward Mr. Snowden, with 34 percent of respondents describing him as “more of a traitor” while 55 percent said he was “more of a whistle-blower.”

Whereas I find Quinnipiac’s broader question on national security to be quite meaningful, I’m not sure that the one about Mr. Snowden tells us very much. The problem is that the sympathetic response toward him in the poll may reflect a sympathetically worded question.

The poll described Mr. Snowden as “the national security consultant who released information to the media about the phone scanning program.” However, Mr. Snowden has also released information to the news media about other N.S.A. activities, such as those it has conducted in China. Some Americans may be pleased by Mr. Snowden’s disclosures about how the N.S.A. conducted surveillance against U.S. citizens – but displeased that he has also disclosed details about its international surveillance. The Quinnipiac poll should probably have described a fuller spectrum of the information that Mr. Snowden has released.