(Bloomberg) -- Fifteen months after Donald Trump’s first travel ban set the in-your-face tone for his presidency, the controversy finally comes before the Supreme Court in a showdown over the limits of the president’s power to control who enters the country.
In arguments Wednesday, the justices for the first time will directly confront the policy, which in its latest version restricts entry by people from seven countries, five of them predominantly Muslim.
The court will consider whether the travel ban’s roots lie in anti-Muslim comments Trump made during his campaign, whether he overstepped his authority under immigration laws and whether judges can second-guess the president’s national-security assessments.
The case will mark the biggest test yet of Trump’s relationship with the court, which so far has treaded lightly around his unconventional presidency. The argument will be the last of the court’s nine-month term.
The justices hinted they will uphold the travel ban when they issued an order in December letting it take full effect during the legal fight. The move, over the dissents of Justices Ruth Bader Ginsburg and Sonia Sotomayor, superseded an order that let an earlier version of the ban take only partial effect.
Still, neither action addressed the merits of the legal controversy, a subject covered by dozens of briefs filed in the case by interested outsiders.
‘Class of Aliens’
The justices will examine a ruling against Trump by a federal appeals court in San Francisco that said he exceeded his powers with a sweeping prohibition from entry to the U.S. that would cover more than 150 million people. Although federal immigration law says the president can block a "class of aliens," the appeals court said he still must show they would be a danger to the country.
Trump’s top Supreme Court lawyer, Solicitor General Noel Francisco, said the appeals court ruling "would severely constrain the ability of this and future presidents to discharge their duties."
Francisco said in a court brief that Trump’s order laid out the reasons for his policy, even though the law "does not require the president to articulate detailed findings before he may suspend or restrict entry of aliens abroad."
That’s a stance that opponents of the travel ban say would give the president far more power over the nation’s borders than either Congress or the constitution’s framers intended.
"It is stunning what the Department of Justice is saying in terms of how much power they are asking the courts to give to the president," said Hawaii Lieutenant Governor Doug Chin, who led the case against the ban when he served as his state’s attorney general.
The travel ban has come a long way since Trump issued the first version in an executive order a week after taking office. That policy took effect immediately, despite minimal vetting by lawyers and immigration experts, sparking chaos and widespread protests at U.S. airports. Judges blocked the first version, and the administration didn’t bother appealing to the Supreme Court.
Two versions later, the travel ban has at least the appearance of a more carefully considered policy. Announced in September, the current ban was put in place only after national security officials reviewed vetting procedures on a country-by-country basis.
The policy bars or limits entry by people from Iran, Syria, Somalia, Libya and Yemen. The ban also blocks people from North Korea and a handful of Venezuelan government officials, though those aspects of the policy aren’t at issue at the high court.
The Department of Homeland Security can add or remove travel restrictions as conditions change. That happened earlier this month, when Trump removed Chad from the list of restricted countries.
Supporters say courts are ill-equipped to second-guess the president on those sorts of issues.
The president "receives daily classified briefings," said John Malcolm, vice president for the Institute for Constitutional Government at the conservative Heritage Foundation. "Congressional leaders receive classified briefings on a periodic basis. Judges do not get classified briefings."
Critics contend the policy is an exceptionally poor fit for fighting terrorism given that the vast majority of recent attacks on U.S. soil were perpetrated either by longtime residents or by people from countries, such as Pakistan, that aren’t on the list.
Opponents say the travel ban unnecessarily separates families, at times by preventing relatives of U.S. citizens from leaving dangerous countries.
"This means that an Iranian parent cannot visit the United States to see her daughter graduate," said Shoba Sivaprasad Wadhia, an immigration-law expert at Penn State. "This means a Syrian post-doc courted by a university for several years cannot obtain a visa for her studies."
The appeals court also said the policy violated a separate immigration provision that bars discrimination on the basis of nationality. The Trump administration says that provision applies only to visas, not to the entry limits imposed by the travel ban.
The Supreme Court additionally will consider whether Trump is violating the Constitution by discriminating against Muslims. The appeals court didn’t reach that issue, but Hawaii and its allies say it provides a separate basis for overturning the policy.
They point to Trump’s campaign call for a ban on Muslims at the border. In December 2015 he called for "a total and complete shutdown of Muslims entering the United States until our country’s representatives can figure out what the hell is going on."
Francisco, the solicitor general, told the court that discerning a president’s motives based on campaign statements is "inappropriate and fraught with intractable difficulties."
Hawaii and its allies also point to tweets issued by Trump after he became president, including some that endorsed the original travel ban and called a later version "politically correct."
The problem is that the post-inauguration comments are "far more docile," Josh Blackman, a constitutional law professor at South Texas College of Law. "He doesn’t have the sort of vitriol and animus that he expressed on the campaign trail."
A key question will be how much deference the court affords a White House whose hallmarks include inflammatory statements and procedural short-cuts.
"The court will have to wrestle with how much to defer to a president who has created this record of chaos and animus," former Obama administration White House Counsel Neil Eggleston and Washington lawyer Amanda Elbogen wrote in a recent blog post. Given the travel ban’s history, "the courts simply should not reflexively defer to the president’s judgment."
The court will rule by the end of June in the case, Trump v. Hawaii, 17-965.
©2018 Bloomberg L.P.