Or at least that's what the Trump administration wants to get across to the justices.
"Could the president ban the entry of Syrian nationals" if he had evidence that some Syrians had chemical or biological weapons?
Even the lawyer for the challengers had to agree the answer was yes.
The case, known as Trump v Hawaii, will address the president's broad powers to set immigration policy, which the administration says permit Trump's travel ban, one of his hallmark policies since taking office in January 2017. Speaking of a hypothetical candidate for mayor, he asked if what was said during that candidate's campaign was irrelevant if on "day two" of his administration the new mayor acted on those statements.
Throughout his presidential campaign in 2016, Trump repeatedly shouted at his election rallies that there must be "extreme vetting" of Muslims traveling to the country, and called for "a total and complete shutdown of Muslims entering the United States", as part of his efforts, which have continued into his presidency, to whip up a far-right and fascistic base of support. If there was any doubt before that anything Trump tweets while in office can be used against him in a court of law, as well as politically, that travel ban case - no matter its ultimate outcome - has now dispelled it. Earlier versions included Chad, Sudan and Iraq.
The Supreme Court has provided a friendlier forum, however.
Francisco told the court the third version was the result of a painstaking review process to determine which countries did not have procedures in place to screen out those who might intend to harm the United States.
That would have given the government reason to be optimistic, and today's argument might have reinforced that optimism: Although it's always risky to make predictions based on the oral argument, it's hard to see how Hawaii can pick up the five votes that it needs to strike down the president's order.
Justice Samuel A. Alito rejected the notion Trump's order could be considered a "Muslim ban", noting it does not apply to most of the largest Muslim nations. But critics alleged in court, successfully, that it essentially targeted Muslims.
Justice Neil Gorsuch, Trump's appointee, questioned whether the challengers had standing to sue in the first place. "That can't be the law of the United States".
"This is about a perennial problem", said Neal Katyal, a lawyer representing challengers of the travel ban. "It's an order based on a multi-agency review". "If it were, it would be the most ineffective Muslim ban since ... it excludes the vast majority of the Muslim world".
Barbara Bush remembered as role model at Texas funeral
But it wasn't the fact that she attended solo that got the internet talking, with the president nowhere to be seen. Bush, the Obamas, the Clintons, and Melania Trump , and said that we ought to "frame that picture in our minds".
"He can hire and fire anyone he wants", she said, adding that a president could dictate to Cabinet officials what they should approve.
But beyond the travel ban case, the ability of courts to weigh Trump's tweets since he took the oath of office on January 20, 2017, as evidence could affect a number of legal matters in which they could prove crucial, from the ongoing challenges to his order rescinding the DACA program, to matters related to the ongoing Russia probe, potential obstruction of justice and litigation over the infamous Russian dossier.
Kennedy pressed on that point.
But during the second half of the argument, the five conservatives steered away from the issue of bias. Justice Anthony Kennedy, who is often seen as a swing vote, had tough questions for both sides. However, neither Justice seemed receptive to Katyal's arguments against the ban. "This court's precedents bar Congress from vesting such extravagant and unilateral authority in the President". His tone suggested the argument was not one he accepted. This proclamation is about what it says it's about: "foreign policy and national security and we would ask that you reverse the court below". "Our brief says it goes back 100 years". For Bush, the "war on terror" provided the first, key test. The last time the court did that was for gay marriage arguments in 2015. Prisoners at the US military base in Guantanamo Bay, Cuba, won the right to court hearings, and Republican states won the right not to expand their Medicaid coverage. The issue was not raised by any of the court's five Republican-appointed members, who indicated an unwillingness to second-guess Trump on the national security justifications offered for the policy.
When President Donald Trump first issued an executive order for a travel ban a year ago, protesters spilled into Seattle-Tacoma International Airport. He cited as examples President Jimmy Carter's order barring Iranians in the late 1970s and President Ronald Reagan's order blocking Cubans in the mid-1980s.
Lower courts again blocked Version 3.0, but the administration has successfully brought its appeal to the highest court, persuading the court to allow implementation while it reviews the case. The first version was blocked by courts and withdrawn. "Congress has never authorized judicial review" of executive decisions "to exclude aliens overseas", Francisco said.
Francisco also has said in written arguments that Trump's September proclamation laying out the current policy comports with immigration law and does not violate the Constitution because it does not single out Muslims. Hussein is also from Somalia and has been directly affected by the ban.
And Mr. Katyal said, the president could have repudiated the statements he made, but he never did. Usually, the "establishment of religion" issue arises when local officials choose to hold prayers at public events or put religious symbols on public property.
Katyal says the "evidence is overwhelming that [the travel ban order] was issued for the unconstitutional goal of excluding Muslims from the United States".
The Supreme Court will most likely make a decision about the travel ban around June.