The future, then, holds a Supreme Court where Chief Justice John G. Roberts Jr.is the swing vote - a scary eventuality for progressives. He said the voices of millions of Americans heading to the polls this fall "deserve to be heard".
Speaking to reporters aboard Air Force One en route from Washington to his private golf club in New Jersey, Trump said he may interview two contenders for the nomination this weekend.
Senate Majority Leader Mitch McConnell blocked President Barack Obama from filling the vacancy created by Justice Antonin Scalia's 2016 death.
Supreme Court vacancies have become a key voting issue in the USA presidential elections.
"I think it's inappropriate to discuss", he added.
De Sousa said he understood the significance because of his background as a constitutional lawyer.
Supreme Court ruling upholds Trump's travel ban
Venezuela and North Korea have also been targeted. "The Court's decision today fails to safeguard that fundamental principle". Whoever replaces him will have a massive sway in the direction of the nation's highest court, possibly for decades to come.
After months of sparse activity in PredictIt's "Who will be Trump's next Supreme Court nominee?" contracts, trading was brisk following Kennedy's retirement announcement. "We're hoping there will be some Democratic support", he said, "We're not assuming this is just going to be a straight party-line vote".
He was often referred to as the "swing vote" between the four more liberal and four more reliably conservative justices now presiding over the court. "Usually they don't say that".
He was among several senators who met Thursday with Trump at the White House.
The Supreme Court has adjourned for the summer without any sign that a justice is retiring.
Trump's nominee must win confirmation by the Senate. And they might get their first post-Kennedy victory very soon, as there is a major case that court is considering taking up having to do with legislative prayer. Though Kennedy declined to reject this term outright a baker's argument that he can discriminate against gay wedding cake seekers, the decision he and six other justices joined was only narrowly in the baker's favor and did not make a sweeping judgment on whether business are allowed to deny LGBT people services. He has advised Trump in the past on judicial picks.
Legal battles are already developing over newly enacted laws restricting abortion, including one in Arkansas that effectively bans medication abortions. "We shouldn't vote on confirmation until they have voted at the ballot box".
It will be his second Supreme Court pick, one that will give him an opportunity to cement the conservative majority on the nation's high court for years to come.
In a statement issued after the verdict, President Trump declared the Supreme Court judgement a "profound vindication" and said he would continue to defend the "sovereignty, safety and security of the American people and fight for an immigration system that serves the national interest of the United States and its citizens".