WASHINGTON, April 25 (Reuters) - Conservative U.S. Supreme Court justices on Wednesday signaled they are likely to uphold President Donald Trump's travel ban targeting several Muslim-majority countries, one of the most contentious policies of his presidency.
Both Chief Justice John Roberts and Justice Anthony Kennedy, a frequent swing vote on the conservative-majority, nine-member court, indicated unwillingness to second-guess the president on the national security justifications offered for the policy.
Trump has said the travel ban - the third version of a policy he first sought to implement a week after taking office in January 2017 - is needed to protect the United States from terrorism by Islamic militants. The current travel ban, announced in September, prohibits entry into the United States of most people from Iran, Libya, Somalia, Syria and Yemen.
The challengers, led by the state of Hawaii, have argued the policy was motivated by Trump's enmity toward Muslims and that it violates federal immigration law and the U.S. Constitution's prohibition on the government favoring one religion over another.
Liberal justices indicated sympathy toward Hawaii's arguments.
But conservative Justice Samuel Alito said the text of Trump's proclamation announcing the ban "does not look at all like a Muslim ban."
Fellow conservative Roberts questioned whether the president could be restricted from taking action on foreign policy emergencies, such as the civil war in Syria, if he is prevented from targeting specific countries.
Kennedy, a conservative who sometimes joins the liberals in major rulings, pushed back on the notion pressed by the challengers that the ban was permanent, noting that the policy includes a requirement for ongoing reports that could potentially lead to the removal of a targeted country.
In an exchange with Hawaii's lawyer, Neal Katyal, Kennedy indicated it was not practical for a president to predict that six months after the ban was announced there will be a "safe world."
Trump's own conservative appointee to the court, Neil Gorsuch, suggested that the lawsuits challenging the ban brought by Hawaii and others should not have been considered by courts in the first place.
Referring to statements Trump made during his campaign for president such as calling for "a total and complete shutdown of Muslims entering the United States," Trump administration lawyer Noel Francisco said those should be off-limits for courts to scrutinize because he was not the president at the time.
In the first half of the argument, Kennedy did signal that courts should be able to review words from candidates from the campaign trail. Kennedy gave the example of a local mayor who makes discriminatory statements and then two days after taking office acts on them.
"You're saying that everything he said is irrelevant?" Kennedy asked Francisco.
'HEART OF HEARTS'
Liberal justices Elena Kagan and Sonia Sotomayor pressed Francisco on what kind of campaign trail behavior could be considered by courts. Kagan asked whether a hypothetical vehemently anti-Semitic candidate would be subject to court review if upon taking office he announced policies targeting Israel.
Would the president's national security rationale suffice, she asked, "even if in his heart of hearts he harbored animus?"
The court is due to issue a ruling by the end of June.
Until Wednesday, the court had never heard arguments on the legal merits of the travel ban or any other major Trump immigration policy, including his move to rescind protections for young immigrants sometimes called Dreamers brought into the United States illegally as children.
It previously acted on the Republican president's requests to undo lower court orders blocking those two policies, siding with Trump on the travel ban and opposing him on the Dreamers.
Trump's hardline immigration policies have been a key part of his presidency, also including actions taken against states and cities that protect illegal immigrants, intensified deportation efforts and limits on legal immigration.
The Supreme Court on Dec. 4 signaled it may lean toward backing Trump when it granted on a 7-2 vote his administration's request to let the ban go into full effect while legal challenges played out.
Chad was on the list of countries targeted by Trump that was announced in September, but Trump removed it on April 10.
Venezuela and North Korea also were targeted in the travel ban. Those restrictions were not challenged in court.
U.S. Attorney General Jeff Sessions in a statement on Wednesday cited the president's "broad discretion and authority to protect the United States from all foreign and domestic threats."
About 150 people demonstrated against the travel ban outside the courthouse on a rainy morning in the U.S. capital. Seema Sked, 39, stood before the court's plaza with a homemade sign that read, "Proud American Muslim."
"The Muslim ban offends freedom of religion, which is a protected right," said Sked, who immigrated with her parents from Pakistan when she was a toddler and now lives in Virginia. "It hurts me because it is singling out and demeaning Muslims because of their faith."
(Reporting by Lawrence Hurley and Andrew Chung; Additional reporting by Mica Rosenberg and Susan Heavey; Editing by Will Dunham)