During his administration, President Obama signed an executive order that would allow "Dreamers" (those brought to the U.S. as young children and grew up here) to stay in this country. The program he created was called DACA -- and if these young Americans had served in the military or gotten an education, and stayed out of legal trouble, then they could qualify. It was a good program, and is supported by a majority of Americans.
But Donald Trump doesn't like the program, and to appeal to his xenophobic and racist base, he signed an order that would end the DACA program and deport these young people (even though most of them have only known this country).
Trump's order was stopped by a U.S. District Judge. Trump then appealed that all the way up to the Supreme Court -- where he thought the new conservative majority would support him and let him deport the Dreamers. He was wrong!
On Thursday, the Supreme Court issued their decision on Trump's attempt to end DACA. In a 5 to 4 decision, they said Trump could not end DACA. Chief Justice Roberts joined four other justices (Ginsburg, Sotomayor, Breyer, Kagan) in striking down the attempt to end DACA, and wrote the decision. Four justices opposed the decision (Alito, Gorsuch, Thomas, Kavanaugh).
The decision doesn't totally protect DACA. It just ruled that Trump had tried to end it without giving good reasons for doing so, and that was a violation of the law. Roberts wrote:
We do not decide whether DACA or its rescission are sound policies. “The wisdom” of those decisions “is none of our concern.” Chenery II, 332 U. S., at 207. We address only whether the agency complied with the procedural re- quirement that it provide a reasoned explanation for its ac- tion. Here the agency failed to consider the conspicuous is- sues of whether to retain forbearance and what if anything to do about the hardship to DACA recipients. That dual failure raises doubts about whether the agency appreciated the scope of its discretion or exercised that discretion in a reasonable manner. The appropriate recourse is therefore to remand to DHS so that it may consider the problem anew.
The Trump administration could always try again to end the program by giving legitimate reasons for ending it (if such reasons exist). But it is unlikely to happen before the November election. That's because the program, while hated by Trump's base, is supported by most voters.