Final answer:
Roosevelt's 1937 court-packing proposal faced criticism for potentially disrupting the separation of powers by allowing the President to appoint additional justices sympathetic to the New Deal, despite its justification as a means to enhance the court's efficiency.
Step-by-step explanation:
President Franklin D. Roosevelt's proposal to expand the Supreme Court membership in 1937 raised criticisms as it was seen as a threat to the principle of separation of powers. Critics argued the plan, often referred to as the "court-packing scheme", would undermine the judiciary's independence by allowing Roosevelt to appoint additional justices who were likely to support his New Deal policies.
Despite advocating for efficiency, the proposal was controversial because it responded to the Supreme Court's decisions that struck down aspects of the New Deal as unconstitutional, suggesting the real intent was to influence court decisions.
The backlash from both the public and members of his party demonstrated a prevailing wariness towards the expansion of executive power and led to a quick reversal of the plan.
Ultimately, the court also began to uphold New Deal legislation before any legislative action on the proposal, with justices like Charles Evans Hughes and Justice Owen Roberts changing their views on federalism, which some have interpreted as an attempt to avoid further conflict.