The CNBC All-America Economic Survey found 34 percent of respondents "very worried" about a major terror attack in the United States.
The mass shootings in San Bernardino have awakened American fears of a major terrorist attack on U.S. soil, bolstered public support for increased monitoring of terrorists in the U.S. and raised concerns over flying and visiting the mall.
The CNBC All-America Economic Survey found 34 percent of respondents "very worried" about a major terror attack in the United States, up from 26 percent before the San Bernardino massacre.
In a finding with significance for the presidential race, 28 percent of Democrats now say they are very worried, up 8 percentage points. Democrats are still not as concerned as Republicans, 45 percent of whom say they are very worried, a 5-point gain.
(A note on the survey: The pre-San Bernardino results are from an initial poll of 800 Americans conducted for CNBC by Hart Research and Public Opinion Strategies Nov. 29-Dec. 2. The poll has a margin of error of 3.5 percentage points. Following the attack, pollsters re-interviewed 347 of the original respondents Dec. 5-7. The new poll has a margin of error of 5.2 points, and provides a unique look at how attitudes changed just before and just after the attack.)
The survey found that Americans' new fears could have some real economic impact, with 42 percent saying they are either extremely or very concerned about flying internationally, 29 percent saying they are concerned about flying on airplanes and 16 percent reporting worries about visiting shopping malls.
They could also revive the political debate about how far the government should go in battling terrorists.
By 52 percent to 33 percent, the highest level since 9/11, more Americans now fear that the government will not go far enough in monitoring the activities and communications of potential terrorists living in the country. In a separate NBC/Wall Street Journal poll in January, Americans were split 46 percent to 47 percent. Nearly half of Democrats are now afraid the government will not go far enough, a significant shift from just before the Dec. 2 attacks in San Bernardino.
And the new results are a near reversal of 2013. At the height of the revelations about government privacy intrusions from NSC contractor Edward Snowden, a 56 percent majority was more worried about the government going too far.
However, Americans are not as convinced about giving up their privacy when it comes to their personal software and devices.
In CNBC survey questions asked only before the San Bernardino attack, 53 percent said technology companies should sell software and devices with encryption coding because it protects consumer data from criminals and protects the privacy of people's personal communications from being read by the government. Only 36 percent thought the companies should not sell the software because it allows criminals and terrorists to communicate secretly.
Companies like Apple and Google have been under scrutiny in recent weeks because of their encryption technology that prevents others, including law enforcement officials, from reading a user's e-mail and text messages.
Only 40 percent of CNBC's survey respondents were familiar with the issue. Among those most likely to say technology companies should sell this technology were millennials and men. Republicans and Democrats were about evenly split, perhaps a sign that the issue has not yet become political as the nation digests recent terror threats and attacks.