President Donald Trump is being sued by two state attorneys general over what they say are his violations of the emoluments clause of the Constitution.

The attorneys general, who spoke to Business Insider, have gotten further in their suit than any others who have tried to sue Trump over the arcane clause.

They could uncover his tax returns in discovery if they keep scoring legal victories.

Two state attorneys general were able to do what no other parties who sued President Donald Trump over an obscure part of the Constitution could.

Now, they have a June date circled on their calendars and say they could obtain the president's highly sought-after tax returns within a matter of months, should they keep racking up wins.

Maryland Attorney General Brian Frosh and Washington, DC, Attorney General Karl Racine explained to Business Insider how they were able to clear a hurdle that other challengers couldn't, laid out their ultimate aim, and detailed what they hope to obtain from the president in their under-the-radar lawsuit that could have big implications for the president.

The lawsuit first garnered attention last month when US District Judge Peter J. Messitte ruled that Frosh and Racine had standing to sue Trump over claims he was violating the Constitution. Others who attempted to challenge the president over earnings his business has made from foreign and state-level government officials at his properties weren't able to clear this hurdle of proving legal standing in such a suit.

How the attorneys general were able to get this far

The attorneys general told Business Insider that the key part of their argument in proving standing involved their claim that both of their state's economies were being harmed by foreign dignitaries and state officials, like Republican Maine Gov. Paul LePage, opting to stay at the president's Washington, DC, hotel over competitors in their area. The federal judge agreed with their argument, which allowed their suit to be the first that cleared the standing hurdle.

Another crucial aspect, they said, was that the lawsuit was being brought forth by state attorneys general instead of a watchdog group. Frosh said in forming their argument, they worked closely with the watchdog group Citizens for Responsibility and Ethics in Washington, Harvard law professor Laurence Tribe, and lawyer Deepak Gupta.

However, there was an aspect of the ruling that the Trump Organization said it was pleased with. The judge's ruling narrows the scope of the case to limit the lawsuit to Trump's Washington, DC, hotel. Trump's business said the court would dismiss the case after it ruled on additional arguments.

"I think that was spin if you want to know," Racine told Business Insider. "I think they were floored that we established standing. And I think that they are concerned."

Frosh said he "would've preferred" if Messitte gave them broad standing, but added that the attorneys general "can work with what he gave us."

"We were very pleased with the decision," he said. "I think it is a very common-sense analysis of the law."

Trump's Washington, DC, hotel. Gabriella Demczuk/Getty If Trump was "pleased" by the more narrow scope, Frosh continued, "let's just get down to the business of discovery and get it over with."

Frosh doesn't believe the president and his business are pleased with the ruling, though.

"This was not a good ruling for them," he said. "I think it's been very clear during the campaign, since the campaign, that Donald Trump does not want to show anybody anything about his businesses, his financial transactions, and his income."

What's next

The next step in the case will take place June 11 before Messitte. In that hearing, the judge will hear arguments over what exactly defines an emolument. And the result of that hearing could springboard the discovery process, where the attorneys general can request certain financial documents related to the finances of Trump's DC hotel — including the president's tax returns.

The emoluments clause bars public officials from receiving gifts or cash from foreign or state governments.

Both Frosh and Racine said the emoluments argument would be easier than initially establishing standing in the case.

The judge could deliver a ruling following the June 11 hearing within a matter of weeks, Racine said.

"This judge is extremely well-prepared based on the prior hearing," he said. "Pretty much knows where he is going. ... That decision could come as soon as September, but it might even be earlier. This judge is not joking around here. He took two months on standing, and standing was hard. This in my view is not that hard."

The Justice Department, which is representing Trump in the case, argued that only profits could be considered emoluments, and that Trump has pledged not to take any profits from foreign government officials at his DC hotel. Already, the Trump Organization has donated what it says are the total profits made at the hotel from foreign government officials to the Treasury Department.

But Frosh said this is a simple misunderstanding of the emoluments clauses related to foreign and state governments.

"You don't have to do much more than read the clauses" to know that's wrong, he said.

After the judge rules on the emoluments issue, Frosh said "we will see discovery immediately." That battle is likely to be met with appeals by the Justice Department, and the case could move up to the US Appeals Court for the 4th Circuit.

But discovery could still move forward even while the 4th Circuit Court debates whether to take on the case.

"Obviously, we're going to say there is no need to delay discovery," Frosh said. "The Justice Department will say there is no need to infringe on the president's personal information, therefore you should stay discovery."

Frosh said the attorneys general will seek Trump's business financial information, including his personal tax returns, to see "who's paying him, how much, and for what."

Racine said obtaining the returns is "a possibility."

"We've got to be as measured as the court was," he said. "And we have to really pursue discovery consistent with the rules. And the rules do allow for a broad range of discovery. But we have to be careful not to turn this into an unbridled fishing expedition."

'We want to cut off the potential sources of corruption'

The ultimate aim here by the attorneys general is to take Trump out of receipt of revenues from the Trump hotel. Prior to taking office, Trump opted to pass his stake in the company to his two sons and a senior executive at the business instead of divesting himself of the assets, as past presidents had done and as ethicists implored him to do.

"Whether Trump is corrupt or not, we want to cut off the potential sources of corruption," Frosh said. "We want to cut off the blandishments. ... We don't want him to be tempted. We don't have to prove a quid-pro-quo in this case. All we have to do is prove a quid."

Racine, who used to work in the White House counsel's office under former President Bill Clinton, said Trump could do something very simple to make this entire lawsuit go away.

"This is where you take a step back," he said. "All the president has to do to end this case is to simply firmly and fully and transparently take himself out of the receipt of revenues. That's it."

"From a practical standpoint, it's almost shocking that he's not doing that," he continued. "And instead, he's going to test the Constitution of the United States, an arcane clause that's never been tested in federal court. It's rather stunning."