Until Adams cooked up his scheme

America was the first country to attempt a Constitutional Republic. The founders greatly distrusted a Democracy and made sure we did not have one. To quote Mel Gibson (who I am sure was quoting someone else) "Why should I trade one tyrant 3000 miles away for 3000 tyrants one mile away"?

The founders set up the federal government with a limited set of powers and even added the bill of rights after to assure that those powers could not grow. But it lasted only until Adams cooked up his scheme to have the Supreme Court determine what it meant and usurp all the power to the feds.

So, no we didn't lose it in the 1920, we lost it in the early 1800s shortly after it was written.

It was completely gone by the end of the FDR regime