Banning all travel into the U.S. from certain Muslim-majority countries was a centerpiece of Candidate Trump's immigration policy proposals. A week after President Trump took office he issued a 90-day executive order barring visitors and refugees alike from Iraq, Iran, Syria, Yemen, Somalia, Sudan and Libya. He exempted religious minorities (Christians) from the order.

On March 6, after federal courts struck down that order, the Trump Administration issued a revised version which removed the exemption for religious minorities, removed Iraq from the list, and contained no specific wording regarding Muslims, among other changes.

Federal courts ruled against that version, as well. Considering Trump's inflammatory statements that indicate the purpose of the ban was a "complete shutdown of Muslims" coming to the U.S., the courts found it likely the order was in bad faith. They then issued injunctions preventing the order from going into effect until the issues could be fully litigated.

Now, according to Reuters, Trump has asked the U.S. Supreme Court to step in on an emergency basis and strike down that injunction. If it does so, the policy would go into effect while it is litigated. However, the Supreme Court rarely grants emergency requests.

Why do the president's Tweets matter for the travel ban?

The president generally has the power to exclude foreigners from the nation in the interest of national security. However, in a 2015 Supreme Court immigration case, Justice Anthony Kennedy wrote that the president's powers cannot be used in bad faith.

The solicitor general defending the order argues that it is urgently necessary to protect our national security.

The order's opponents claim it is too broad, that it discriminates against otherwise-innocent Muslims, and that the six countries targeted don't even represent the nations with the most prominent ties to terrorism. They also call the government's urgency into question.

The lower courts took Trump's campaign Tweets into account when evaluating the travel ban, because his inflammatory language could imply bad faith.

The president's Tweets are likely to be at issue again, if the U.S. Supreme Court takes up the case. For example, shortly after the petition was filed, a dissatisfied trump Tweeted that the Justice Department ought to have sought the high court's approval of his original order, "not the watered down, politically correct version they submitted to" the Supreme Court.

The question before the high court might be, "what was politically incorrect about the original ban, if not its apparently racist purpose?"