来源：www.history.com
An executive order is an official directive from the U.S. president to federal agencies that often have much the same power of a law. Throughout history, executive orders have been one way that the power of the president and the executive branch of government has expanded.
行政令是美国总统向联邦机构发出的官方指令，通常具有与法律同等的效力。纵观历史，行政令一直是总统和政府行政部门权力扩张的一种方式。
What is an Executive Order?
The U.S. Constitution does not directly define or give the president authority to issue executive orders. Instead, this implied and accepted power derives from Article II of the Constitution, which states that as head of the executive branch and commander in chief of the armed forces, the president “shall take Care that the Laws be faithfully executed.”
美国宪法没有直接规定或赋予总统发布行政令的权力。实际上，这一隐含和公认的权力来自《宪法》第二条，该条规定，总统作为行政部门首长和武装部队总司令，“应注意忠实执行法律”
With an executive order, the president instructs the government how to work within the parameters already set by Congress and the Constitution. In effect, this allows the president to push through policy changes without going through Congress.
总统通过行政令，指示政府如何在国会和宪法规定的范围内工作。实际上，这使得总统可以在不通过国会的情况下推动政策改革。
By issuing an executive order, the president does not create a new law or appropriate any funds from the U.S. Treasury; only Congress has the power to do both of these things.
总统发布行政令，既不能制定新的法律，也不能从美国财政部挪用任何资金；只有国会有权做这两件事。
How an Executive Order is Carried Out
Any executive order must identify whether the order is based on the powers given to the president by the U.S. Constitution or delegated to him by Congress.
任何行政令都必须确定该命令是基于美国宪法赋予总统的权力，或是由国会授予总统的权力。
Provided the order has a solid basis either in the Constitution, and the powers it vests in the president or in laws passed by Congress, an executive order has the force of law.
只要在宪法、以及宪法赋予总统的权力或国会通过的法律中有坚实的基础，行政令就具有法律效力。
After the president issues an executive order, that order is recorded in the Federal Register and is considered binding, which means it can be enforced in the same way as if Congress had enacted it as law.
总统发布行政令后，该命令会被记录在《联邦公报》上，并被认为具有约束力，这意味着它可以像国会颁布法律一样执行。
Checks and Balances on Executive Orders
Just like laws, executive orders are subject to legal review, and the Supreme Court or lower federal courts can nullify, or cancel, an executive order if they determine it is unconstitutional.
和法律一样，行政令也要接受司法审查，如果最高法院或下级联邦法院认定行政令违宪，可以撤销或取消。
Similarly, Congress can revoke an executive order by passing new legislation. These are examples of the checks and balances built into the system of U.S. government to ensure that no one branch—executive, legislative or judicial—becomes too powerful.
同样，国会可以通过新立法撤销行政令。这些都是美国政府内部制衡的例子，以确保没有任何一个部门——行政、立法或司法——变得过于强大。
One prominent example of this dynamic occurred in 1952, after Harry Truman issued an executive order directing his secretary of commerce to seize control of the country’s steel mills during the Korean War.
这种动态的一个突出例子发生在1952年，当时朝鲜战争期间，哈里·杜鲁门发布行政令，命令商务部长接管美国的钢铁厂。
But in its ruling in Youngstown Sheet & Tube Co. v. Sawyer later that year, the Supreme Court ruled that Truman’s order violated the due process clause of the Constitution, and that the president had not been given statutory authority by Congress to seize private property.
但在那年晚些时候，最高法院在<扬斯敦材料管公司诉索耶>案的裁决中裁定，杜鲁门的行政令违反了宪法的正当程序条款，而且国会没有给予总统没收私人财产的法定权力。