Adam Liptak

It is invalidating what is the cornerstone of President Trump's economic policy, sweeping implications for the economy and, of course, for presidential power.

This is a massive, devastating and consequential blow for this administration.

It's also a rare rebuke.

It's good to be here.

Well, this is a court that's been very favorable to President Trump.

But here we have the first major argued merits decision on really the centerpiece of a domestic and international program.

And the court says that the main statute he relies on does not authorize him to do what he wants to do.

So this is a major blow from a court that not everyone expected to stand up to President Trump.

So this case is about a congressional statute.

the International Emergency Economic Powers Act.

So this is not about the Constitution.

It's about whether Congress has, under this law, authorized presidents to impose tariffs.

And it's always been a stretch because this law doesn't include the word tariffs or a synonym like duties.

Instead, it's kind of a word salad that includes a lot of words.

And the administration is focused on two of those words, the regulation of importation.

And even those words are separated by 16 other words.

And Chief Justice Roberts, writing for six justices, says that just doesn't bear the weight.

that the administration wants to place on it, that Congress has the power to tax, and tariffs are, of course, an import tax, and Congress, if it wants to authorize the president, can, but it didn't here.

And regulation is not the same as taxation, Chief Justice Roberts says, so he thinks this is a fairly straightforward grammatical exercise.

That's right.