America has changed fundamentally since -- and away from -- the values that President Franklin Delano Roosevelt represented both in his words, and in his actions (that's to say, in his actual decisions, his choices, as the U.S. President). Though President Barack Obama isn't radically different from FDR in his words, he's almost the opposite of FDR in his real governing values and decisions, his real leadership of the United States.
Unfortunately, most people see politics only by words, and ignore realities. But, in some important respects (his actions, his decisions), Barack Obama is -- and I hate to say this -- actually closer to FDR's enemies, Benito Mussolini and Adolf Hitler, than to FDR. This is true not only regarding the contrast between FDR's moving America away from enormous wealth-inequality, versus Obama's moving America toward even higher wealth-inequality than before; it's yet more starkly exhibited in the international policies of these two post-economic-crash U.S. Presidents, as will be demonstrated here.
FDR was viscerally and actively anti-fascist and anti-nazi, whereas Obama simply is not. FDR was anti-aristocracy; Obama is pro-aristocracy. FDR was pro equal-rights; Obama is actually anti equal-rights. That's the reality, not the rhetoric.
So, first, here's FDR:
Roosevelt believed strongly in equality of rights for all people, even more so than did Winston Churchill, who was a supremacist as regards the alleged special 'right' of the British people to rule over the people in India and throughout the remaining colonies of the British Empire. (FDR opposed all empires.) The third member of World War II's Allied troika of anti-fascists and of anti-nazis, Joseph Stalin, wasn't merely an imperialist like Churchill was -- he didn't even believe in democracy at all, not even for his own people. In fact, before Hitler invaded Stalin's USSR in "Operation Barbarossa" on 22 June 1941, Stalin was allied with Hitler. However, Stalin wasn't a nazi, nor even a fascist at all: he was a communist. He rejected capitalism, he didn't reject only democracy.
So, let's first clarify the terms, in order to understand what it means to say that America has changed, from democracy to fascism, and now even to nazism:
Fascism is dictatorship by and for capitalists; i.e., for the owners of corporations, for the controlling stockholders in the biggest firms; that's to say, for the aristocracy. Mussolini, the first person to establish a fascist government, once defined fascism that way, and approvingly called it also "corporationism." He believed in privatizing state assets, which he did in 1922-25; see Germa Bel's "The First Privatization: Selling SOEs," in the 2011 Cambridge Journal of Economics. (Also here.) Then, Hitler took up privatization; see Bel's "Against the Mainstream: Nazi Privatization in 1930s Germany," in the 2010 Economic History Review. Chile's Pinochet, England's Thatcher, and America's Reagan, weren't the first privatizers: privatization went all the way back to fascism's very founding. It merely became revived after 'libertarianism' (which was actually invented by fascist aristocrats -- primarily the DuPonts -- in the 1930s) blossomed after WWII, because (their beloved) fascism had developed a bad reputation after losing that global war.
Nazism (with a small n, "nazi"; not the German party, which was "Nazi") is simply racist fascism (the racist form of fascism). Not all fascists are racists: for examples, Italy's Mussolini wasn't a racist, and Spain's Franco also wasn't. They weren't opposed to racism; they simply weren't concerned about it at all. Just as fascism that's spelled with a small f is the ideology instead of being the political party that started it (in Italy); nazism with a small n is the ideology rather than the political party that started that ideology (in Germany).
There are fascists throughout the world, just as there are nazis throughout the world. And, the particular type of supremacism (or "racism") that different nazis spout, can differ from country to country; so that, for example, nazis from one country can even go to war against nazis from another country, because they want global supremacy for different groups of people.
Similarly, different nazisms might have different hatreds, different types of bigotries: Germany's nazis during the 1930s hated Jews the most, whereas Ukraine's nazis hate Russians the most. And, if, in WWII, Germany's Hitler and Japan's Tojo had won control respectively of the West and the East, then a war between those two nazis, Hitler and Tojo, might have resulted, in order to subordinate the one of them to the other of them. Nazi countries can, and sometimes do, go to war against each other.
So: basically, nazism is racist fascism. It's also -- and more precisely -- known as supremacist fascism. A good example of a fascist who was not a supremacist is Spain's Franco.
Another way to think of nazism is as its being extremist fascism; and, in this sense, we today know of ISIS and Al Qaeda as Islamic nazi groups, or as Islamic supremacist-fascist groups. Everyone knows that they are also extremists.
Mussolini's teacher, Vilfredo Pareto, was called "the Karl Marx of fascism," and his core message was that the democratic belief that each person has the same rights is false; that there is a natural hierarchy; and that inferiors naturally exist for the benefit of their superiors. This attitude is at its most extreme in nazis, all the way from Hitler to ISIS; it extends to all supremacists.
Whereas peace can exist among democracies, nazisms are always at war; it's their nature; it is their essence, because they are supremacists. They demand their own supremacy. (In America, some nazis are called "Dominionists." It's just a form of supremacism.) That's why nazis tend to be especially attracted to war: war truly is their natural condition.
Regarding the other two types of dictatorships: Fascisms and communisms aren't necessarily always at war: for examples, Spain's Franco was peaceful after winning power, and Cuba's Castro could have been peaceful if the U.S. hadn't been constantly trying to overthrow him. There is nothing intrinsically supremacist about either fascism or communism, though both tend toward a certain amount of supremacism, because they both deny equality of rights; but nazism is intrinsically supremacist; nazism is supremacism; supremacism is nazism. By contrast, a mere fascist can be satisfied to be supreme only at home, without extending it abroad to dominate the entire world.
Nazism is the most dangerous ideology that exists. It is the most extreme denial of equality of rights. It is the most extreme denial of democracy. It doesn't just say that aristocrats are superior; it says that everyone else should be their slaves, or else dead. It is the most extreme embodiment of Pareto's view.