The real decline started after Edward Snowden and all the information that came out about the NSA. It really sparked distrust in the government. Trying to get people to respond to surveys was already hard, why would those general people believe the Census Bureau is actually keeping their data safe? Doesn’t matter when it comes to laws and the constitution, if you work for an Agency. You are the government. Response rates keep going down, now we have attacks from the President on statistics about the economy. I’m a little cynical and I just assume they will continue to shrink the statistical agencies and make the statistics more useless (which is what this recent policy change does), and they will shift to the private industry. Even though the private industry cannot do the work in the Field that the government does.
I buy the argument that a functioning democracy requires the populace to believe that the government is honest, competent, and working in their interests. Watergate, Iran-Contra, and the Vietnam war (respectively) undermined those notions. As of ~2016, half of the US voting population had come of age after those events.
> The real decline started after Edward Snowden and all the information that came out about the NSA. It really sparked distrust in the government.
Do you have evidence of this? Because I'd bet 90% Americans have no idea who Edward Snowden even is.