DAVID GREENE, HOST:
On Monday, a team of ethics lawyers and legal scholars filed suit claiming that President Trump's many foreign business dealings violate the Constitution.
STEVE INSKEEP, HOST:
They cite the Emoluments Clause, a provision in the Constitution that bars presidents from accepting gifts or money from foreign governments.
GREENE: Of course, one big question courts will have to decide is not actually about the merits of the case here but rather just who has the legal standing to challenge the president in court. Here's NPR's Jim Zarroli.
JIM ZARROLI, BYLINE: It is a fundamental concept in the law. If you want to sue someone successfully, you have to prove first that you've been hurt by them. Michael McConnell is a professor at Stanford Law School.
MICHAEL MCCONNELL: If your neighbor is hit by a car, you may be outraged, you may think he ought to sue, but you can't sue on his behalf. He's the only one who can sue.
ZARROLI: In recent years, the Supreme Court has become a lot stricter about determining whether a plaintiff in a suit has the standing to sue. And so the group now suing Trump, Citizens for Responsibility and Ethics in Washington - or CREW - has to show how it has been damaged by Trump's conflicts. CREW has done this by arguing that it's had to put extra time and resources into publicizing and opposing Trump's actions. One of the lawyers arguing the case, Deepak Gupta, says CREW needs to be looked at like a business whose product is ethics reports and commentary.
DEEPAK GUPTA: Because of Donald Trump's unprecedented conflicts of interest, the cost to produce that product has gone up. The resources had to shift away from the business that they engage in typically, and that affects them.
ZARROLI: Gupta says there's precedent for this argument. In 1982, the Supreme Court ruled that a housing advocacy group could sue a real estate firm because it was consuming its resources by discriminating against tenants. Still, Stanford's Michael McConnell thinks CREW's argument is a stretch.
MCCONNELL: This is not even a close case of standing. An organization doesn't have standing because it chooses to throw resources into an issue. If that were true, anyone would have standing to challenge anything.
ZARROLI: If CREW doesn't have the standing to sue the president over his conflicts of interest, then who does? One possibility is Trump's business competitors. A hotel could argue that it's being hurt because its customers are switching to Trump properties to curry favor with the president. And CREW has already heard from some Trump competitors who say that's happening, Gupta says.
GUPTA: And we are considering very carefully the potential claims that those people have.
ZARROLI: Or the courts could decide that nobody really has the standing to sue the president and that it's ultimately up to Congress to decide if the president's conflicts are a problem. Jonathan Adler, professor of law at Case Western Reserve University, says, in that case, the primary mechanism for dealing with the problem is impeachment.
JONATHAN ADLER: It's obviously something that's unlikely when Congress is controlled by the same party, but that is the structure.
ZARROLI: In the meantime, the plaintiffs in this week's lawsuit are hoping to convince the courts they have the standing to challenge the president. Jim Zarroli, NPR News, New York.
(SOUNDBITE OF MATT JORGENSEN'S "SPACE, PLANE AND LINE")