The United States could have been considered a social democratic country, back when Franklin D. Roosevelt made the "New Deal" reforms. I would argue that the erosion of those reforms is the reason the U.S. is in such dire straits today.
It was those reforms that set America up for the decline that it has been in ever since;
Do you have evidence to support that claim?
that have established precedents by which our government has strayed ever farther from the model defined for it in the Constitution, and ever deeper into corruption and tyranny. FDR may have meant well, but he, alone, has done more to damage this nation than any other President.
Could you explain why you believe that FDR was responsible for these things?
To radically oversimplify a much more complex story than I have time or patience to tell right now, and which is not terribly relevant to this thread anyway…
With his reforms, FDR seized massive, unprecedented powers on behalf of the federal government, far beyond what it was legitimately authorized under the Constitution to exercise. He employed threats, intimidation, and other corrupt means to coerce the courts into going along with his blatantly-unconstitutional usurpations. By doing so, and by the precedents that he thus established, he effectively gutted the Tenth Amendment, and began an avalanche of further illegal usurpations on the part of the federal government that have continued ever since.
Just to give one example, of the sort of damage this has caused.
In the 1910s, there was a very strong movement that wanted to outlaw the production and trade of alcoholic beverages nationwide. It was then clearly and correctly understood that as the Constitution stood, the federal government had no legitimate authority to do so, and that there was only one legitimate way that this prohibition could be put into effect. See the Eighteenth Amendment. About a decade or so later, when the public changed its mind, the same method had to be employed in order to reverse it. See the Twenty-First Amendment.
Prior to the ratification of the Eighteenth Amendment, the federal government did not have any authority regarding alcoholic beverages, nor does it have any authority, after the passage of the Twenty-First Amendment, which repealed the Eighteenth Amendment. The federal government didn't have this authority, and the only way it could be given this authority was to amend the Constitution.