When Donald Trump announced his Muslim ban on 27 January, pandemonium erupted. Lawyers everywhere raced to airports. Galvanized by Trump’s threat to liberty, they rapidly assembled legal theories and commenced a still unbroken siege of Trump’s bigoted policy. As attorneys stockpiled caffeine, the American people rallied by moonlight outside terminals and federal courts.

The legal response to Trump’s emoluments clause violations has taken shape more slowly. And understandably so: until recently, most Americans had never heard of “emoluments”. Only in the past few months – aided by creative public art and a high-profile lawsuit – has the public come to appreciate that Trump’s conflicts on interest are forbidden by the constitution.

It’s no coincidence that this arcane issue has newfound salience. We’re now witnessing kleptocracy on an unprecedented scale in America. And there’s barely even a fig leaf of cover. Trump has openly enmeshed his private financial interests in national policy. To say that this creates an appearance of corruption would be far too polite. This is the real deal: sketchy dealings all the way down.

Until recently, a rough bipartisan consensus would have thwarted such open corruption. But it’s now clear that the Republican party has made a deal with the devil, trading integrity (their own and the government’s) for a shot at long-held dreams. Surprising nobody, the devil is already far ahead in this stupid, crooked bargain.

But if recent events are any sign, the public will not stand idly by as Trump turns our nation into a banana republic.

The opening legal salvo was fired on Trump’s first working day in office. Then, Citizens for Responsibility and Ethics in Washington (Crew) filed suit against the president under the foreign and domestic emoluments clauses. Their case has attracted widespread interest and attention, and has since grown with the addition of new private plaintiffs.

Just last Friday, Trump’s lawyers at the Department of Justice filed a motion arguing that Crew’s case should be dismissed. That filing has drawn heavy criticism from experts including Leah Litman, Andy Grewal and Marty Lederman. It takes true chutzpah to argue that requiring the president to stop receiving money from enemy foreign powers would “distract [him] from his constitutional responsibility to ‘take Care that the Laws be faithfully executed’”.

Yet perhaps most shocking is a suggestion, near the end of this lengthy brief, that nobody can ever hold the president accountable in court for his unconstitutional conduct.

As I have explained – and as Richard Primus details at the Take Care blog – this is wrong. The president can’t serve as judge and jury for his own emoluments. While Congress plays a role in reviewing foreign emoluments, that role is limited: the plain text of the constitution provides that foreign emoluments are illegal – and remain illegal – unless Congress says that the president can keep them.

Where Congress sticks to its usual course of doing absolutely nothing, or is improperly denied even a chance to vote on the question, the president may not keep foreign emoluments. End of story. If he does keep foreign emoluments and thereby causes harm, the injured party may file suit in federal court to remedy the president’s wrongdoing.

For months now, however, Crew has stood alone in federal court. That isn’t surprising: going from zero to 60 on major constitutional litigation is no easy feat.

This week, everything changed. The stakes of Trump’s ongoing illegal conduct are now much higher.

On Monday, Maryland and the District of Columbia filed an emolument suit of their own against the president. This case is exceptionally persuasive. As Washington DC and Maryland explain: “Uncertainty about whether the President is acting in the best interests of the American people, or rather for his own ends or personal enrichment, inflicts lasting harm on our democracy. The Framers of the Constitution foresaw that possibility, and acted to prevent that harm.”

Reading the complaint, I would not want to be a justice department lawyer tasked with defending this case – especially since Trump, at any moment, could burn my credibility with a single tweet. He’s done it before.

In all likelihood, Trump’s main substantive response will be to argue that Maryland and Washington lack standing to bring their claims against him. But for reasons that Larry Tribe and I discuss at length on Take Care, that would miss the mark.

In short, two theories of standing support this new case. First, Washington and Maryland own businesses that now compete on tilted terrain against the president’s own properties, which Trump has transformed into emolument vortexes. And second, they invoke uniquely sovereign and quasi-sovereign interests that are violated by Trump’s decision to embrace rampant corruption.

For example, Maryland observes that its entry into the Union depended in part on prohibitions against officials accepting payments from federal, state or foreign governments. If Maryland and Washington are to retain their equal sovereignty within our federal system, and to enjoy the benefits of that order, they should not be forced to feather Trump’s nest.

The law of state standing is no model of clarity, and these arguments will be challenged. Ironically, many of those attacks may come from conservatives who spent the past eight years obsessively thinking up creative new theories for Texas to sue Barack Obama. As it turns out, those same conservatives now feel differently with their party in control of the federal government, facing lawsuits from progressive states. In the end, though, there is great force to the view that Washington and Maryland are proper plaintiffs to challenge Trump.

On Wednesday, 196 members of Congress opened up still another front in the war for American democracy. Their lawsuit targets Trump’s foreign emoluments, many of which remain cloaked in secrecy that thwarts legislative oversight. As Brianne Gorod explains: “By failing to go to Congress and seek its consent, [Trump] denies members of Congress an opportunity to which they are entitled under the Constitution – to give or withhold their consent to his acceptance of these benefits from foreign states.”

Anti-kleptocracy cases initially got off to a slow start under Trump. But the pace of suits attacking his conflicts will increase as these issues move to the core of our national agenda. With private plaintiffs, states and federal legislators before them, courts will soon have to decide whether to order Trump to follow the constitution.

For the sake of our democracy, it would be gravely disappointing were judges to abandon the field, allowing Trump’s corruption to sink deeper roots.

To borrow a warning from Justice William O Douglas: “As nightfall does not come at once, neither does oppression. In both instances, there is a twilight when everything remains seemingly unchanged. And it is in such twilight that we all must be most aware of change in the air – however slight – lest we become unwitting victims of the darkness.”

Disclaimer: Joshua works closely with lawyers involved in both the Crew and Maryland/Washington DC cases challenging Trump’s receipt of emoluments.

• This article was amended on 14 June 2017 to include the latest lawsuit against Donald Trump, which was filed over night.