Each of the last three presidents has publicly vowed that Americans will not be intimidated by terrorism or its threats and will continue to live their normal lives as the deadly struggle endures until who-knows-when.

Easier to vow such stuff when you’ve got 24-hour, lifetime Secret Service protection.

Now comes evidence that, in fact, ordinary Americans — forget about the big-shots — are already adjusting their lives to the threat of terrorism by hesitating before joining large crowds. A new Gallup survey has just discovered that fully 38% of adult Americans say they now are less willing to put themselves in large crowds for fear of the possibility of terrorism.

That’s up significantly from the 27% who said that just six years ago. Now, given 16 years of increasing terrorist incidents at home and abroad, including unpredictable vehicular attacks on pedestrians, that 38% is the highest Gallup has recorded since after 9/11, when 30% expressed that concern before that fear sagged.

That’s an understandable concern actually given tightened airport security and the recent attacks in Manchester and London, Tuesday’s bombing attempt in Brussels, Monday’s in Paris, last summer’s Nice bus attack, the 2013 Boston Marathon bombing, the San Bernardino shootings and last year’s mass shooting at Orlando’s Pulse nightclub, among others.

If that trend continues, the economic and political impacts on events with large attendance — parades, sporting events, marathons, concerts — could be significant, if currently unpredictable.

Fully 60% now say it is somewhat or very likely that a major domestic terrorist attack will occur in the next several weeks. That’s a rather sharp increase from the 38% who said that in the summer of 2011 and even the 45% who said that just two years ago.

Forty-six percent of the 1,009 adults surveyed by Gallup June 7 to 11 said they are now less willing to travel abroad, up eight points since 2011. Almost one-third (32%) are more hesitant to fly commercially, up from 24%. And 26% are less willing to enter a skyscraper now, the highest number in 15 years.

Despite the security promises of their party’s president, Republicans express the most concerns about flying, traveling abroad or attending events with large crowds.

Despite these growing concerns, a sizable 70% of Americans say they have a great deal or fair amount of confidence in the federal government’s ability to protect citizens from any future terrorist attacks. No one said that fears of unseen threats — sharks, radiation, oncoming terrorists — had to be rational.