To hear President Trump tell it, the nation is facing a rebellion in Los Angeles, an invasion by a Venezuelan gang and extraordinary foreign threats to its economy.

若是按照特朗普总统的说法，这个国家正面临三重危机：洛杉矶的叛乱、一个委内瑞拉黑帮的入侵，以及来自外部的严重经济威胁。

Citing this series of crises, he has sought to draw on emergency powers that Congress has scattered throughout the United States Code over the centuries, summoning the National Guard to Los Angeles over the objections of California’s governor, sending scores of migrants to El Salvador without the barest hint of due process and upending the global economy with steep tariffs.

基于这些所谓的危机，他试图动用国会几个世纪以来散布在《美国法典》各处的紧急权力：不顾加州州长反对向洛杉矶调遣国民警卫队，未经正当程序将大批移民遣送至萨尔瓦多，通过高额关税扰乱全球经济。

Legal scholars say the president’s actions are not authorized by the statutes he has cited and are, instead, animated by a different goal.

法律学者指出，总统援引的法条并未授权他采取这些行动，而且他在这些事上别有所图。

“He is declaring utterly bogus emergencies for the sake of trying to expand his power, undermine the Constitution and destroy civil liberties,” said Ilya Somin, a libertarian professor at Antonin Scalia Law School who represents a wine importer and other businesses challenging some of Mr. Trump’s tariffs.

安东宁·斯卡利亚法学院的自由派教授伊利亚·索明表示，“他正在通过捏造紧急状态来扩张权力、破坏宪法并摧毁公民自由。”索明代理一家葡萄酒进口商和另外几家公司，正在对特朗普的一些关税提出挑战。

Crisis is Mr. Trump’s brand. When he took office the first time, he promised to end “American carnage.” When he announced his most recent re-election campaign, he said he would reverse “staggering American decline.” Ever since he first ran for president in 2015, he has argued that only he can restore the country to greatness.

危机叙事是特朗普的标识。他在第一个任期曾经承诺要结束“美国浩劫”。在宣布再次竞选时，他声称要扭转“惊人的美国衰落”。自2015年首次竞选总统以来，他一直标榜唯有自己才能让美国再次伟大。

Now in office again, he is converting that rhetoric into policy. Mr. Trump says that events and circumstances largely considered routine amount to emergencies that allow him to invoke powers rarely sought by his predecessors but embedded in statutes by lawmakers who wanted to ensure presidents could act quickly and aggressively to confront authentic crises.

如今再度上台，他将这种说辞转化为政策。特朗普将普遍被视为常态的事件定性为紧急状态，借此动用历任总统鲜少动用、但由立法者写入法律条文的权力。这些权力本来是国会为了让总统能够快速应对真实危机而设定的。

Frank O. Bowman, a law professor at the University of Missouri, said the laws Mr. Trump has invoked were premised on a presumption that the flexibility they granted would not be abused.

密苏里大学法学教授弗兰克·O·鲍曼表示，特朗普援引的法律是基于一种假设，即它们所赋予的灵活性不会被滥用。

“Genuine emergencies do occur, and Congress knows that it’s slow,” Professor Bowman said. “It wants presidents acting in good faith to move with rapidity.”

“真正的紧急情况确实会发生，国会也知道自己行动缓慢，”鲍曼说。“它希望秉持诚信的总统能迅速行动。”

But Professor Bowman said Mr. Trump’s approach was different. “Declaring everything an emergency begins to move us in the direction of allowing the use of government force and violence against people you don’t like,” he said.

但鲍曼指出，特朗普的做法截然不同。“将一切事态都宣布为紧急状态，这种做法正将我们推向允许政府对你不喜欢的人动用武力或暴力手段的方向，”他说。

In a statement, the White House spokeswoman Taylor Rogers said that Democrats had failed “to protect Americans from economic and national security threats — inaction that has resulted in serious crises.”

白宫发言人泰勒·罗杰斯在一份声明中表示，民主党人未能“保护美国民众免受经济和国家安全威胁——这种不作为已经酿成了严重危机”。

“President Trump is rightfully using his executive authority — as evidenced by many victories in court — to deliver resolve and relief for the American people,” she said.

“特朗普总统正在正当行使行政权力——这从他在法院赢得的多项胜诉中可见一斑——为美国民众带来坚定的举措与切实的纾解，”她说。

In fact, lower courts have for the most part rejected Mr. Trump’s assertions of emergency powers.

事实上，下级法院在很大程度上驳回了特朗普对紧急权力的主张。

In March, Mr. Trump invoked the Alien Enemies Act of 1798, which grants the president the power to deport citizens of nations engaged in war, invasion or “predatory incursion,” arguing that Tren de Aragua, a violent Venezuelan gang, was invading the United States. The law had been used just three times before, in the War of 1812, in World War I and in World War II.

3月，特朗普援引1798年《敌对外国人法》——该法案授权总统驱逐与美国处于战争、入侵或“掠夺性侵犯”状态的国家的公民——声称委内瑞拉暴力犯罪集团“阿拉瓜火车”正在入侵美国。这项法律此前仅被用过三次，分别是在1812年战争、第一次世界大战和第二次世界大战期间。

Several judges have now rejected the idea that the gang’s activities justified the use of the law.

目前已有数位法官裁定，该犯罪团伙的活动不足以构成援引此项法律的条件。

There is nothing in the 1798 law, Judge Alvin K. Hellerstein of the Federal District Court in Manhattan ruled last month, that “justifies a finding that refugees migrating from Venezuela, or TdA gangsters who infiltrate the migrants, are engaged in an ‘invasion’ or ‘predatory incursion.’”

曼哈顿联邦地区法院法官阿尔文·海勒斯坦上月裁定：1798年的法律中没有任何条款“能够证明来自委内瑞拉的难民或混入移民群体的阿拉瓜火车黑帮成员构成了‘入侵’或‘掠夺性侵犯’。”

“They do not seek to occupy territory, to oust American jurisdiction from any territory, or to ravage territory,” wrote Judge Hellerstein, who was appointed by President Bill Clinton. “TdA may well be engaged in narcotics trafficking, but that is a criminal matter, not an invasion or predatory incursion.”

“他们不寻求占领领土，或寻求推翻美国在任何领土上的管辖权，也不寻求蹂躏领土，”由克林顿总统任命的海勒斯坦法官写道。“‘阿拉瓜火车’或许确实从事贩毒活动，但这属于刑事犯罪，而非入侵或掠夺性侵犯。”

One judge, Stephanie L. Haines, of the Federal District Court for the Western District of Pennsylvania, a Trump appointee, ruled the other way, saying the gang has engaged in a “predatory incursion.”

然而，由特朗普任命的宾夕法尼亚州西区联邦地区法院史蒂芬妮·海恩斯法官做出了相反的裁决，称该帮派进行了“掠夺性侵犯”。

Even apart from the 1798 law, Mr. Trump has embraced the rhetoric of a nation under siege, promising amid stepped-up ICE raids and violent protests in California to “take all such action necessary to liberate Los Angeles from the Migrant Invasion.”

即使抛开1798年的法律不谈，特朗普还渲染“国家受到围困”的论调，在移民与海关执法局突击搜查和加利福尼亚州暴力抗议活动升级之际，他宣称将“采取一切必要行动，将洛杉矶从移民入侵中解放出来”。

Mr. Trump used a similar justification for imposing tariffs in April, saying that “foreign trade and economic practices have created a national emergency.” Two courts have ruled against him, though an appeals court has temporarily paused the broader of the two rulings.

特朗普在4月加征关税时也使用了类似的理由，称“外国的贸易和经济行为已造成国家紧急情况”。两家法院已裁定他败诉，尽管一家上诉法院暂时中止了其中适用范围较广的一项裁决。

特朗普总统在加州调动了数千名国民警卫队员，宣称将“采取一切必要行动，将洛杉矶从移民入侵中解放出来”。

California officials on Monday disputed Mr. Trump’s assertion that there was a crisis in the state that required an extraordinary federal response when they announced a lawsuit over his takeover of a unit of the state’s militia. “The situation in Los Angeles didn’t meet the criteria for federalization, which includes invasion by a foreign country, rebellion against the authority of the government of the United States and being unable to execute federal laws,” state officials said in describing the suit.

加州官员在周一驳斥了特朗普所谓加州正面临危机、需要联邦采取非常措施的说法，并宣布他们就总统接管该州民兵部队的一个单位提起诉讼。州政府官员在说明诉讼理由时表示：“洛杉矶的局势不符合联邦接管的标准，而这些标准包括：外国入侵、反抗美国政府权威，以及无法执行联邦法律。”

The Supreme Court has yet to weigh in on Mr. Trump’s recent assertions of emergency powers. In the past, the justices have at times been skeptical of such claims. They did not hesitate, for instance, to reject President Joseph R. Biden Jr.’s invocations of the Covid pandemic to take emergency actions.

美国最高法院目前尚未对特朗普总统近期有关紧急权力的主张作出裁定。从历史判例来看，大法官们对此类权力主张往往持审慎态度。举例来说，他们曾毫不迟疑地驳回了拜登总统以新冠疫情为由采取的紧急措施。

Two notable provisions of the Constitution discuss invasions. One prohibits states from engaging in war “unless actually invaded, or in such imminent danger as will not admit of delay.” The other says that “the privilege of the writ of habeas corpus shall not be suspended, unless when in cases of rebellion or invasion the public safety may require it.”

美国宪法中有两项重要条款对“入侵”作出规定：其一明确禁止各州在“非实际遭受入侵，或面临刻不容缓之紧迫危险”的情况下参与战争；另一条款则规定“人身保护令特权不得中止，除非发生叛乱或入侵事件，且基于公共安全之必需”。

The court’s most significant ruling on a president’s emergency powers came in its 1952 decision in Youngstown Sheet and Tube Company v. Sawyer, which rejected President Harry S. Truman’s claim that a national emergency — there, the Korean War — allowed him to nationalize steel mills in the face of labor strikes.

联邦最高法院就总统紧急权力作出的最重要裁决，当属1952年《扬斯敦钢铁公司诉索耶案》——该案否决了哈里·杜鲁门总统以朝鲜战争构成国家紧急状态为由，强行将钢铁厂国有化以应对工人罢工的主张。

The decision included a canonical concurrence from Justice Robert H. Jackson, a touchstone that Supreme Court nominees routinely praise at their confirmation hearings.

在那项裁决中，罗伯特·杰克逊大法官撰写了一份协同意见书，该意见书已成为一块试金石，经常在最高法院席位确认听证会上得到提名人们的称赞。

Justice Jackson wrote that the framers of the Constitution were wary of granting the president emergency powers.

杰克逊大法官在意见书中指出，宪法的制定者对授予总统紧急权力始终持审慎态度。

“They knew what emergencies were, knew the pressures they engender for authoritative action, knew, too, how they afford a ready pretext for usurpation,” he wrote. “We may also suspect that they suspected that emergency powers would tend to kindle emergencies.”

他写道：“他们深谙紧急状态的本质，清楚其带来的强制性行动，更明白这往往成为权力僭越的现成借口。我们或许还可以推测，他们还在想紧急权力本身可能可以激发出更多紧急情况。”