The best one can say in Roosevelt's defense is that he prevented something worse, a Communist takeover. I suppose it was possible.
There was never a possibility of a Communist takeover of the US. What was possible was a Socialist takeover of the Democratic party, which is what FDR engineered and turned into a Socialist takeover of the US. Luckily, he was forced by patriots to keep his hands of the Supreme Court and some of his most vile Socialist plans were thwarted.