主题：修宪相当于三大战役，是一次关键的胜利 -- ANS

Within the executive branch itself, the president has broad powers to manage national affairs and the priorities of the government. The president can issue rules, regulations, and instructions called executive orders, which have the binding force of law upon federal agencies but do not require approval of the United States Congress. Executive orders are subject to judicial review and interpretation.

此外，总统还有广泛的人事权。

Before taking office, the president-elect must appoint more than 6,000 new federal positions. The appointments range from top officials at U.S. government agencies, to the White House Staff, and members of the United States diplomatic corps. Many, but not all, of these positions at the highest levels are appointed by the president with the advice and consent of the United States Senate.[8]

至于你说的美国需要“强化中央政府的权力才能解决一些问题”，这见仁见智，因为不同的美国人眼里的美国的问题并不相同。美国社会自身没有关于要解决的问题的共识，你也不能指望美国联邦政府能够在你认定的问题上集中权力。

上面的资料来源于 https://en.wikipedia.org/wiki/Powers_of_the_President_of_the_United_States

和美国相比，中国社会的一个优势是有共识。自1949年第一共和国成立以来，建立文明、强大、富裕的社会主义现代化国家是每个中国人都认同的目标。即便是反党分子，也无法否认这个目标的合理性和吸引力。共产党在意识形态上的优越性是中国实现长期快速发展的根本原因。

然而共产党体制的不足之处就是缺乏明确、民主而可行的权力传承体制。总书记、常委、政治局委员、中央委员会重峦叠嶂，权限不明，易于引发政变。这是悬在中国现代化进程上空的半定时炸弹。中共和苏共都没有解决这个问题。