We should know who President Trump is financially beholden to -- a lawsuit might make that happen

In the judge’s ruling, the key term is emolument. The plaintiffs, the attorneys general of both Maryland and the District of Columbia, argue that emoluments are “any profit, gain, or advantage.” This interpretation would include payments made by foreign governments to the Trump Organization, such as stays at the Trump International Hotel in Washington. Those payments are key, despite the trust set up by the president that supposedly separates him from his business empire, since that money still goes back to Trump and would thus be in violation of the Constitution. U.S. District Judge Peter Messitte found this argument persuasive.

Messitte found that, specifically, the plaintiffs plausibly alleged that president’s profiting from his hotel and direct benefit from the patronization of foreign governments has meant that Trump “has been receiving or is potentially able to receive ‘emoluments’ … in violation of the Constitution.”

That ruling paved the way for the lawsuit to progress. That could mean that if the court allows the case to proceed to discovery, then Trump’s tax returns could be scrutinized as lawyers examine Trump’s business dealings and the payments that he has received.