Government ethics lawyers have widely condemned Trump for holding onto his vast business empire after taking office.
They argue that gives plenty of opportunity for people who want to influence US policy to curry favour with the president. In the motion to dismiss, Trump and his lawyers said the Maryland Attorney-General's argument that business in his state will get hurt by Trump's Washington, DC, hotel is too "speculative," among other faults.
The Attorney-General had argued that businesses hurt by Trump competition will cut into tax revenue.
In response to similar lawsuits, Trump and his lawyers have also argued that critics are misinterpreting the emoluments clauses.
They say that the framers of the Constitution did not intend for them to cover fair-value transactions between a business and its customers, such as offering a hotel room for the night for payment.
Trump owns and licenses hotels and resorts around the world, but his decision to hold onto his lavish hotel in Washington is especially troubling to Trump critics.
Since inauguration, the Trump International Hotel has hosted parties by foreign embassies and become a favourite gathering spot for lobbyists.
On Thursday, Supreme Court Justice Neil Gorsuch gave a speech at the hotel. The choice of the venue was widely criticised by liberal groups.
At a news conference when the lawsuit was filed in June, District of Columbia Attorney-General Karl Racine highlighted what he sees as damage from foreign government attempts to use Trump's holding to their advantage.
"We're concerned that foreign governments are coming to the Trump businesses with a single purpose of currying special favour from the president of the United States so that their interest can get a higher priority than the interest of the American people," Racine said.
"If that's not a harm to every American citizen and every resident in the District of Columbia and Maryland, I don't know what is."
If a federal judge allows the case to proceed, Racine has said he will demand copies of Trump's personal tax returns in court to gauge the extent of his foreign business dealings.
