That’s largely a myth. There are many reasons to be concerned about the constitutional impact of the NDAA, PATRIOT Act, and the War on Terror in general. But as far as the powers of your local sheriff or state highway patrol are concerned, they have had zero impact.
That being said, be mindful that some police officers may use the threat of terrorism to trick citizen’s into believing they have enhanced search and interrogation powers. For example, police may justify a routine traffic search request by claiming “I’m just searching for guns and explosives”. This is simply a cynical way to trick citizens into compliance.
Don’t fall for it. You have the right to refuse search requests by asking ”Officer, am I free to go.” Repeat if necessary.