Suffice it to say that, at least thus far, a compelling case to diminish my estimation of Calvin Coolidge has not been made in this venue. I still honor his place as among the true greats who held the office.
As for the "open borders" matter, Calvin Coolidge's statement makes his position abundantly clear:
American institutions rest solely on good citizenship. They were created by people who had a background of self-government. New arrivals should be limited to our capacity to absorb them into the ranks of good citizenship. America must be kept American. For this i purpose, it is necessary to continue a policy of restricted immigration. It would be well to make such immigration of a selective nature with some inspection at the source, and based either on a prior census or upon the record of naturalization. Either method would insure the admission of those with the largest capacity and best intention of becoming citizens. I am convinced that our present economic and social conditions warrant a limitation of those to be admitted. We should find additional safety in a law requiring the immediate registration of all aliens. Those who do not want to be partakers of the American spirit ought not to settle in America.
Plus there were budget surpluses each year during Coolidge's presidency. I really can't how a connection can be drawn from his prudent fiscal policies to the Great Depression.
And Coolidge did nothing ~ apparently thinking that prohibitory tariffs against American products and food were good for somebody ~ certainly not Americans.
What I blamed Coolidge for was for creating the environment that allowed the Great Depression to occur, as he did by advocating high protective tariffs.