特朗普总统旨在限制邮寄选票使用的紧急上诉，即将考验美国最高法院一项颇具争议、已有 20 年历史的司法原则。设立该原则的初衷，是避免大选前夕选举规则出现动荡。
这项名为珀塞尔原则（Purcell principle） 的准则源自最高法院 2006 年一项判决，核心要求：联邦法院不应在临近选举时临时更改投票相关规则。但该原则此前从未在涉及联邦选举政策的案件中接受最高法院检验。特朗普此番试图授权美国邮政局与国土安全部筛查各州选民登记名单，排查潜在非公民选民，正是典型案例。
最高法院 6 名保守派大法官、3 名自由派大法官将如何运用这条由本院创立、饱受争议的规则，不仅将决定本案走向，也会影响今年秋季、以及 2028 年总统大选前夕潮水般涌向最高法院的各类选举诉讼。
保守派选举政策组织 “诚实选举项目” 副主席查德・恩尼斯表示：“本案中联邦机构的行动，有可能直接改变 2026 年中期选举的运作方式。案情十分特殊，最高法院届时是否适用、如何适用珀塞尔原则，目前一切都是未知数。”
特朗普在今年 3 月签署行政令，要求各州向美国邮政局提交合格选民名单；邮政局不得向名单以外人员寄送选票。行政令还要求各州在选票信封上添加可追踪条形码，并要求联邦层面优先起诉那些向无投票权人士（包括非公民）收发选票的州级选举官员。
行政令同时要求国土安全部整理各州符合投票资格的美国公民选民清单。
波士顿联邦法院此前裁定暂缓实施这份行政令。上周，特朗普就此向最高法院提起紧急上诉。这份上诉文书暂未讨论行政令本身是否合法，也没有直接提及珀塞尔原则。但如果最高法院在本案部分诉求上支持特朗普，今年晚些时候围绕这项司法准则的激烈交锋将无可避免。
多个由民主党主政的州一同起诉挑战这份行政令。各州在周一向最高法院警示，若行政令落地，后果不堪设想。 “这份行政令彻底改变美国邮政局的职能，不仅严重背离美国选举由地方分权管理的传统，更会给民主制度带来巨大威胁。仓促编制新选民名单、启用尚未经过实测的选票核验技术，极易出现人为失误，大量选民或将因此被剥夺投票权。”
最高法院预计将于本月下旬作出裁决。 避免选举混乱？
正是因为珀塞尔原则，诉讼时机几乎成为所有投票规则联邦诉讼的核心争议点。
去年 12 月，最高法院允许得克萨斯州启用新版国会选区地图，这份地图有利于共和党掌控众议院，部分理由就是初选将在 3 月举行。
2024 年，最高法院援引珀塞尔原则，批准路易斯安那州使用一套利好民主党的国会选区划分方案，州政府提出的理由是候选人报名截止日期临近。
再往前两年，距离阿拉巴马州初选仅剩大约一个月，下级法院裁定当地共和党划定的选区地图削弱黑人选民政治力量，但最高法院大体依靠珀塞尔原则，保留了这套地图。最高法院简短裁定文书没有直接引用该原则，但布雷特・卡瓦诺大法官撰写附随意见，长篇论证该准则适用合理性。
卡瓦诺写道：“本院多次明确，临近选举时，联邦法院原则上不应强制叫停州选举法规。这项珀塞尔原则，是选举法的基石：选举将至，投票规则必须清晰、稳定。”
但批评者指出，最高法院多数派的标准前后不一。当年路易斯安那州初选邮寄投票已经启动，法院却允许该州立刻切换至偏向共和党的选区地图；新版地图设立第二个黑人占多数选区的旧方案就此作废。自由派大法官基坦吉・布朗・杰克逊当时提出质疑：为何有的案件法院急于干预，另一些案件却拒绝在选举前夕出手？
杰克逊指出，路易斯安那州的上诉审理期间，全州选举正在进行。 “法院抛开原本的约束，直接介入纷争。所谓司法原则，在权力面前轻易让步。”
保守派大法官塞缪尔・阿利托严厉反驳杰克逊。他表示，杰克逊希望沿用的旧选区地图，几天前刚被最高法院裁定违宪。并且在最高法院作出《路易斯安那州诉卡莱》判决后，该州众议院相关选举投票已经暂停。
特朗普这起邮寄选票上诉案目前尚未直接触及珀塞尔原则，但起诉行政令的各州希望最高法院充分考量该准则，防止陷入两难困局。
特朗普的核心主张是：各州与相关组织起诉时机过早。一旦最高法院采纳特朗普观点，各州只能延后重新发起诉讼。等到诉讼重启，时间将逼近 11 月大选，届时联邦政府就可以搬出珀塞尔原则，阻止法院介入审查。
加州等一众民主党主政州周一恳请最高法院提前堵住这种可能性：要么驳回联邦政府的紧急申请，至少明确规定联邦政府不能后续再拿珀塞尔原则当挡箭牌。
各州诉状写道：“倘若联邦政府现阶段胜诉，那么它完全可以转头，等到选举临近时援引珀塞尔原则，规避实质性司法审查。”
特朗普政府司法部辩称，这起诉讼尚未达到审理时机，联邦政府还没有采取任何实际行动执行行政令。行政令本身也没有写明美国邮政局落地细则。
联邦副总检察长 D・约翰・索尔在上诉文书中向大法官表示：“这份行政令只是总统面向下属的内部指令，单凭这份命令，不会改变任何州的选举规则。”
与此同时，联邦政府并未承诺日后不会援引珀塞尔原则。5 月另一场关联本案行政令的庭审中，特朗普任命的联邦地区法官卡尔・尼科尔斯询问控方，未来是否会打出这张牌。政府律师斯蒂芬・佩齐回应，大概率不会，但并未彻底排除该选项。
佩齐称：“站在当下，我无法绝对承诺 8 月份不会提出相关主张。而且在我看来，这项准则能否适用，本身存在巨大不确定性。” 全新法律难题
美国历史上，联邦政府极少直接参与选举管理。以往冲到最高法院的选举争议，几乎全部围绕州一级政策展开。
美国公民自由联盟投票权利项目负责人索菲亚・林・拉金表示，特朗普这份邮寄选票行政令史无前例，本案或将厘清最高法院如何运用珀塞尔原则。
“大量涉及珀塞尔原则的裁决走快速保密通道作出，未必稳定集齐五名大法官支持。外界只能拼凑零散判决，预判法院态度。” 该机构也在马萨诸塞州联邦法院另案挑战这份行政令。
拉金认为，尽管存在珀塞尔原则，仍然有线索显示多数大法官有可能支持叫停行政令。保守派大法官越来越倾向将珀塞尔原则定位为约束联邦法院的工具，避免联邦法院插手州主导的选举事务。
从这个角度来看，这条准则本质上是把选举管理权交给各州，既不属于联邦法院，也不属于联邦行政机构。
“这份邮寄选票行政令越过边界，” 拉金分析，“联邦行政机构无视各州意愿，强行给州选举体系新增临近大选的重大改动。”
圣母大学选举法权威教授德里克・穆勒持相同观点。 穆勒说：“珀塞尔原则更多适用于法院叫停州规则的情形，背后有联邦分权理念支撑。这和联邦政府主动出台选举政策，有着本质区别。”
穆勒还提到，法院审理选举案件考量的不只有珀塞尔原则。如果法官认定联邦政府试图临近大选刻意修改规则、钻制度空子，其他衡平法因素会不利于联邦政府。 “如果一项规则在选举临近时仓促推出，珀塞尔原则约束力会大幅下降。这种情况下，法院依据衡平法理，有权出手干预。”
上周，华盛顿联邦上诉法院在另一起关联案件中，批准特朗普行政令落地。法院在裁决末尾指出，不必担心联邦政府后续利用珀塞尔原则阻碍诉讼。
由三名上诉法官组成的合议庭写道：“原告对珀塞尔原则的理解本末倒置。” 假如联邦政府试图在大选前夕给各州投票体系带来颠覆性改动，即便存在珀塞尔原则，联邦法院依然可以出手制止 —— 这么做恰恰是维持各州现有的选举状态。
值得留意的是，上诉法院得出该结论时，没有引用任何一条最高法院判例作为支撑。
Trump’s mail voting appeal tests Supreme Court’s anti-chaos election rule
President Donald Trump’s emergency appeal aimed atlimiting the use of mail ballotsis poised to test a controversial， 20-year-old Supreme Court principle that was intended to avoid chaos before elections．
The “Purcell principle，” rooted in a 2006 Supreme Court decision，warns federal courts against making last-minute changes to voting rules． But the principle has never before been weighed in a Supreme Court case involving a federal election policy like Trump’s effort to give the US Postal Service and the Department of Homeland Security a handin screening state voter rollsfor potential non-citizen voters．
How the 6-3 conservative majority deals with its self-created and oft-criticized rule in the Trump case could have practical implications for how the court handles the flood of litigation that will inevitably crash onto its docket this fall， and ahead of the 2028 presidential election．
“Here we have potential federal agency action that could impact the way the 2026 election is run，” said Chad Ennis， the vice president of the Honest Elections Project， a conservative group focused on voting policies． “I think this is a novel set of facts and how SCOTUS would apply Purcell， if at all， is an open question．”
Signed in March， the president’s executive order would require states to submit lists of eligible voters to the US Postal Service， which would be barred from sending ballots to anyone not on those lists． It would also require states to use tracking barcodes on ballot envelopes． And it would “prioritize” federal prosecution of state election officials who send or receive ballots to non-citizens or others ineligible to vote．
The order also requires DHS to create lists of what it views as eligible， US citizen voters in each state．
Federal courts in Boston blocked the order’s implementation． Trumpfiled an emergency appeal at the Supreme Courtlast week． That appeal doesn’t deal with the merits of the president’s order， nor does it say anything about Purcell． But if the court sides with Trump on any portion of the case， it will likely set up a showdown over the doctrine later this year．
A group of Democratic states challenging Trump warned of dire consequences Monday if the executive order is allowed to take effect．
“The challenged EO’s transformation of USPS’ role would not only depart markedly from our nation’s tradition of decentralizing the administration of elections， but also pose extraordinary threats to our democracy，”the states told the Supreme Court． “Voters would likely be disenfranchised， as officials inevitably make mistakes in rushing to formulate new voter lists and roll out untested technologies to scan ballots for eligibility determinations．”
The Supreme Court will likely rule in the case later this month．
U．S． President Donald Trump signs an executive order on mail ballots， in the Oval Office of the White House in Washington， D．C．， March 31， 2026． Evan Vucci／Reuters Avoiding chaos？
Because of the Purcell doctrine， timing almost always lurks as a central issue in federal challenges to voting rules．
In December， theSupreme Court allowed Texasto use a congressional map that boosted the GOP’s chances of keeping control of the House， partly because the primary election was set for March．
In 2024， thecourt cited Purcellwhen it allowed Louisiana to use a congressional map that benefited Democrats because the state argued that candidate filing deadlines were fast approaching．
Two years earlier， roughly a month out from Alabama’s primary election， the court appeared to rely on Purcell to keep a congressional map drawn by thestate’s Republicans in place， despite a lower court decision that the map diluted the political power of Black voters． The court’s brief order didn’t cite Purcell， but Justice Brett Kavanaugh wrote a lengthy concurrence defending its application in that case．
“This court has repeatedly stated that federal courts ordinarily should not enjoin a state’s election laws in the period close to an election，”Kavanaugh wrote． “That principle — known as the Purcell principle — reflects a bedrock tenet of election law： When an election is close at hand， the rules of the road must be clear and settled．”
Critics， however， note that a majority of the court was fine allowingLouisiana to revertimmediately to a Republican-friendly congressional map in May even though absentee voting had already started for the primary under a different map that included a second Black-majority district． Justice Ketanji Brown Jackson， a liberal，questioned at the timehow her colleagues could square the hurry-up approach in that case with its reticence to engage at the last minute in others．
Jackson noted that the emergency Louisiana appeal came “in the midst of an ongoing statewide election．”
“The court unshackles itself from both constraints today and dives into the fray，” she wrote． “And just like that， those principles give way to power．”
Her dissent drew a sharp rebuke from Justice Samuel Alito， a conservative， who noted that the map Jackson would have left in place for this year’s election had been ruled unconstitutional by the Supreme Court days earlier． The state had alsosuspended voting in the House contestsafter the Supreme Court’sruling in Louisiana v． Callais．
Purcell is not currently at issue in the Trump appeal over the mail ballots， but the states are likely to ask the court to keep the doctrine in mind to head off a catch-22 scenario． That’s because Trump’s central argument is that the states and groups who are challenging his order sued too soon． If the Supreme Court agrees with Trump， then the states will have to wait to revive their litigation． And that will necessarily push the cases closer to the November election， allowing the administration to raise Purcell to bar courts from weighing in．
California and the other Democratic-led states challenging Trump pleaded with the court on Monday to head off that possibility， either by rejecting the administration’s emergency request or at least making clear that the administration couldn’t attempt to invoke Purcell later．
If the administration wins at this stage， the states said， “nothing would stop them from turning around and trying to invoke the ‘Purcell principle’ to avoid meaningful review as the election approaches．”
Trump’s Justice Department has argued that the lawsuit against the administration isn’t “ripe” because the government hasn’t taken any steps yet to enforce its order． The Trump administration has noted that the Postal Service has not yet officially made clear how it would implement Trump’s order．
“The executive order is an intra-branch directive from the president to his subordinates — which， of its own force， does not change anything at all about elections in any state，” US Solicitor General D． John Sauer told the justices in the administration’s appeal last week．
At the same time， the administration hasn’t said it won’t try to invoke Purcell at a later stage in the case． At a May hearing in a separate case dealing with the same executive order， US District Judge Carl Nichols， a Trump nominee， asked if the administration would try to raise that argument． The administration’s attorney， Stephen Pezzi， said he didn’t think it was likely．
But he also didn’t rule it out．
“I， of course， can’t and won’t take an argument off the table about what the world will look like in August from the lectern today，” Pezzi said． “But it’s far from clear to me that that sort of consideration would apply here．”
Novel questions
Because the federal government has historically had an infinitesimal role in running elections， the last-minute voting cases that race up to the Supreme Court have dealt with state policies．
A voter drops their ballot at an official ballot drop box outside City Hall during a primary election in San Francisco， California， US， on Tuesday， June 2， 2026． David Paul Morris／Bloomberg／Getty Images
Sophia Lin Lakin， director of the Voting Rights Project at the American Civil Liberties Union， described the Trump administration’s executive order on mail ballots as unprecedented． And that means the case may shed light on the court’s approach to Purcell．
“Many of these decisions on Purcell have been handled on the shadow docket in a way that hasn’t necessarily garnered clear support of five justices， so we’ve been at times piecing together different ideas along the way to determine how it might play out，” said Lakin， whose group is challenging Trump’s executive order in a separate case pending in a federal court in Massachusetts．
While Trump’s emergency appeal raises questions the court hasn’t directly addressed， Lakin said she believes there are clues that a majority of justices might vote to intervene to halt the administration’s order， even with Purcell on their minds． Increasingly， the court’s conservatives have framed the principle as a check on the power of federal courts to interfere in elections that are run by states．
In that sense， the doctrine is partly about ceding control to run elections to the states — not the federal courts， nor federal agencies．
“This mail voting executive order sits on the wrong side of the line，” Lakin said． “It’s a federal actor imposing late-breaking changes on state election systems over the objections of the states that run them．”
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Derek Muller， a law professor at Notre Dame who is an expert on election law， agreed．
“Purcell has more weight when you are enjoining a state rule because of federalism concerns，” Muller said． “That on its own is a powerful distinction” from a federal election policy．
The court also considers more than just Purcell when it’s weighing an elections case， Muller said． Those other factors， he said， might disfavor the federal government if courts felt it was attempting to game the system with last-minute changes．
“I also think Purcell doesn’t really work when the rule is being enacted very close in time to the election，” Muller said． “In that circumstance， regular equitable considerations would allow courts to intervene．”
A federal appeals court in Washington， DC，okayed Trump’s executive orderin a separate case last week． In the final paragraph of that order， the court dismissed the idea that the Trump administration would be able to invoke Purcell to shut down a future challenge to its order later this year．
“Plaintiffs’ fear has the Purcell principle backwards，” the panel of three appeals court judges said．
If the administration were to attempt to impose “massive changes on the states’ voting systems on the threshold of the upcoming election，” then federal courts could block that — despite Purcell — because such a move would “preserve the states’ existing electoral status quo．”
The appeals court， tellingly， didn’t cite a single Supreme Court decision to back up that conclusion．
This story has been updated with additional developments．
