A federal judge wrestled Thursday with whether Democratic lawmakers can sue President Donald Trump in a lawsuit one senator called the “only ball game in town” to stop the president from unconstitutionally accepting foreign state gifts without congressional approval.

The first emoluments lawsuit filed against Trump was thrown out in New York in December for lack of standing. Those plaintiffs included a nonprofit group, restaurant workers and business owners. A lawsuit in Maryland involving state attorneys general was allowed to move forward early this year.

Brianne Gorod, chief counsel for the Constitutional Accountability Center representing the Democratic lawmakers, argued that Trump, who as president has not divested from his business empire, denied members of Congress their individual rights to vote on each emolument.

Part of that, she said, was because Trump has accepted gifts and payments “in secret,” and Congress could not weigh in on emoluments the president did not disclose. Publicly reported emoluments—like Chinese trademark approvals or rental payments from foreigners at the Trump hotel—“are only the tip of the iceberg,” Gorod said.

Shumate, representing the government, attempted to persuade the judge that the resolution for the angry lawmakers would be a “political process.” There was “no reason why,” he said, that plaintiffs could not vote on the emoluments issue today.

But Gorod painted the government’s argument as off the mark. She also argued there’s no legislative recourse or “adequate remedy” the congressmen could take to stop Trump from accepting emoluments.

Even if Congress voted to deny Trump any emoluments, the president would need to sign the bill and volunteer to no longer enrich himself. The alternative—a congressional supermajority to override a veto—would be an “extraordinary measure” beyond an adequate remedy to get Trump to comply with the constitution, Gorod said.

Shumate, who took issue with that “adequate” modifier, argued Congress had other political tools at its disposal, like stalling Trump nominees.

But U.S. Sen. Richard Blumenthal of Connecticut, a lead plaintiff, said later at a press conference that those measures were not realistic solutions because they would punish Trump at the cost of the American public. Even if Congress passed a resolution or law to stop Trump from accepting payments, they would still have to go to court to enforce it.

When Shumate first took his turn at the lectern, Sullivan said the government might have “overreached” in briefs when it suggested the president’s refusal to submit to congressional approval before receiving emoluments was “not a judicially cognizable injury.”

Shumate also said that in cases like this, U.S. Supreme Court precedent ruled out the idea that institutional injuries could be brought by individual members of Congress.

Sullivan batted out some of those questions on standing to Gorod, too, and whether the alleged injury in the case applied more to Congress as a body versus individual lawmakers.

The President Bill Clinton appointee asked Gorod whether their argument for standing would be “stronger” if all members of the Senate sued Trump, not just congressional Democrats. He also asked if there was a “magic number” of legislators needed to make the argument for standing more persuasive.

Gorod said that even if it were only one legislator suing, he or she would be able to pursue these claims against Trump because he is depriving each individual member a voting opportunity.

After Sullivan asked Shumate if the government believed any plaintiff would have standing to sue Trump, and Shumate indicated that was unclear, the judge noted it could be “troubling” for the Article III judge to hear there might not be anyone who can get Trump to “comply” with the anti-corruption clause.