Paul Begala, advisor to President Bill Clinton (1998)
One of the oldest traditions in the American republic is "government by an emergency." Over the last 2½ centuries, US citizens have endured confiscation, imprisonment, and censorship conducted outside normal constitutional constraints. The Supreme Court has routinely upheld war and emergency powers claimed by US presidents. In most cases, the majority of Americans have supported these measures.
An executive order is the "law of the land" unless overturned by the Supreme Court or overridden by Congress. That's happened only twice in American history. And if Congress overrides an executive order, the president can always veto it. That means unless two-thirds majorities in both the House and the Senate vote to override the veto, the executive order stays in place.
This is not likely to happen in the Trump administration since both houses of Congress will be controlled by his party, the Republicans. And even if they do, Trump could simply veto that law.
In just over five weeks, President Trump will, at the stroke of a pen, be able to:
Seize the property of any person, entity, or government in the United States. This authority was used to freeze assets in 1941 of several European countries, including Switzerland, six months before the United States entered World War II. In the last two decades, presidents have issued executive orders to seize US assets of Iran, Libya, Kuwait, Serbia, Iraq, Nicaragua, South Africa, and Panama, along with thousands of persons allegedly tied to terrorism. And in case you didn't get the point, in 2006, the Treasury announced that it has the power to confiscate "any financial instrument" in the event of a national emergency. President Trump could use this authority, for instance, to seize the fund's foreign workers in the US often send home to their families. Indeed, Trump has threatened to do just that to fund construction of a wall on the US-Mexican border.
Imprison or detain individuals or an entire class of people without trial. President Lincoln used this authority during the Civil War to suspend the writ of habeas corpus and bring accused political criminals before military tribunals for trial. During World War II, President Franklin Roosevelt ordered more than 100,000 Japanese-Americans living in the western United States to internment camps. The second President Bush used this authority to detain suspected terrorists at Guantanamo Bay, Cuba. If I were Megyn Kelly, I'd be thinking seriously about leaving the US for at least the next four years.
Impose national banking "holidays" closing all US banks. President Franklin Roosevelt used this authority in 1933 to close down the US banking system after a run of bank failures. Alternatively, the president may restrict or ration currency withdrawals and the cashing of checks or drafts.
Investigate, regulate, or prohibit the importing, exporting, or holding of currency, securities, or precious metals. In 1933, President Franklin Roosevelt mandated the sale of all privately held gold bullion held by US persons to the federal government.