Even as the campaign lawsuits brought by President Trump over the 2020 election enter their death throes, many people continue to worry that Mr. Trump will find three Republican legislatures to magically snatch victory from the jaws of defeat. They are concerned that he will pull off an antidemocratic hat trick through maneuvers like delaying recounts in Wisconsin and blocking certification in Michigan to allow these legislatures to submit competing slates of electors to Congress. The goal is to prevent Joe Biden from securing the Electoral College votes he needs on Jan. 6 for Congress to declare him president.

The good news is that there is no real prospect that Mr. Trump can avoid a reluctant handover of power on Jan. 20. The bad news is that Mr. Trump’s wildly unsubstantiated claims of a vast voter fraud conspiracy and the litigation he has brought against voting rights have done — and will increasingly do — serious damage to our democracy. Our problems will deepen, in particular, because Mr. Trump’s litigation strategy has led to the emergence of a voter-hostile jurisprudence in the federal courts. New judicial doctrines will put more power in the hands of Republican legislatures to suppress the vote and take voters, state courts and federal courts out of key backstop roles.

Let’s start on the positive side. A federal district court opinion issued in Pennsylvania Saturday laid bare both the dangerousness and vacuousness of Mr. Trump’s litigation strategy. Rudy Giuliani, acting as one of the president’s lawyers, failed to persuade Judge Matthew Brann — an Obama-appointed Federalist Society member and former Republican official — to disenfranchise nearly seven million Pennsylvania voters and to let the state legislature name a slate of presidential electors. The court held that the Trump campaign offered a “Frankenstein’s monster” of a legal theory and that the complaint was full of nothing more than “strained legal arguments without merit and speculative accusations, unpled in the operative complaint and unsupported by evidence.”

Although the campaign has appealed the case to the Third Circuit, it is so weak it will get no better reception there or at the Supreme Court. There are no remaining legal cases that could plausibly overturn the election results in even one state where Mr. Trump has lost (much less the three he would need for a different result in the Electoral College).

Dilatory tactics like delaying certification or recounts will be rejected by courts or governors, and not even a single state legislature (much less three) seems eager to incur the wrath of the American people through a power grab that would violate the rule of law, trigger massive street protests and call the legislators’ own elections into question. Most state legislators appropriately defer to the will of their own voters despite pressure from the president.

And even if three state legislatures engaged in broadly antidemocratic action by purporting to appoint their own slates of electors, federal law favors Electoral College slates sent in by governors, and we can expect Democratic governors in Michigan, Pennsylvania and Wisconsin to submit slates reflecting their voters’ choice of Mr. Biden. On top of that, Democrats will control the House, which will not accept rogue alternative electors. If Congress stalemates, Mr. Trump is out of office on Jan. 20 under the Constitution’s 20th Amendment.

All of that is indeed good news, but I am quite concerned about what comes next. By the time President-elect Biden takes the oath of office, millions of people will wrongly believe he stole the election. At least 300 times since the election, Mr. Trump has gone straight to his followers on social media to declare the election rigged or stolen and to claim, despite all evidence to the contrary, himself as the real victor. Mr. Trump’s false claims will delegitimize a Biden presidency among his supporters. It should go without saying that a democracy requires the losers of an election to accept the results as legitimate and agree to fight another day; Republican leaders echoing Mr. Trump’s failure to support a peaceful transition of power undermine the foundation of our democracy. It’s not only the fact that we have had to say this, but that we keep having to repeat it, that shows the depths that we have reached.

Mr. Trump’s litigation strategy also will make things worse when it comes to voting rights. The common thread in his campaign’s postelection litigation connecting Trump allegations of people of color illegally voting in Democratic cities in swing states and corrupted voting machines is a lack of any evidence to support the claims. Many of the lawsuits have been laughed out of court for lack of evidence, voluntarily dismissed, or involve so few votes that they could not plausibly change the outcome. These unsuccessful lawsuits will nonetheless provide a false narrative to explain how it is that Mr. Biden declared victory and serve as a predicate for new restrictive voting laws in Republican states. They already provided a basis for the now-aborted attempt of Republican canvassing board members in Wayne County, Mich., to reject votes from Democratic-leaning Detroit, and could be the basis for a similar move by Republicans when the Michigan state canvassing board meets Monday.

And even as Mr. Trump has lost most of his postelection lawsuits, he and his allies had a good bit of success before the election in cases that will stymie voting rights going forward. Following the lead of the U.S. Supreme Court, federal appeals courts now routinely say that federal courts should be deferential when states engage in balancing voting rights — even during a pandemic — against a state’s interests in election administration and avoiding fraud, even when states come forward with no evidence of fraud. Under the so-called “Purcell principle,” courts increasingly allow states to make voting harder. They can do this whenever states are able to stall judicial proceedings long enough that they can claim a voting change comes too close to the election and will confuse voters and election administrators. Courts have issued other disturbing opinions, including allowing for age discrimination in the availability of mail-in ballots only for those older than 60 or 65, essentially short-circuiting litigation under the 26th Amendment, which bars discrimination in voting on the basis of age.

The worst appears yet to come. In one of the lawsuits that remains technically alive at the Supreme Court out of Pennsylvania, Mr. Trump and his allies have advanced a muscular version of something that’s become known as the “independent state legislature” doctrine. Taken to its extreme, the doctrine says that state legislatures have complete authority to set election rules absent congressional override, and that their power to set election rules cannot be overcome even by state supreme courts applying right-to-vote provisions in state constitutions.

That’s the basis for Mr. Trump’s claim in the U.S. Supreme Court that the Pennsylvania Supreme Court order, requiring the receipt of mail-in ballots arriving up to three days after Election Day, had to be counted. (This is now a question for future elections because there are not enough ballots at stake to affect the 2020 count.) The doctrine also could be potentially violated by state and local election agencies even when they act under the Legislature’s authority to administer elections.

In the course of pre-election proceedings, Justices Samuel Alito, Neil Gorsuch, Brett Kavanaugh and Clarence Thomas issued or signed onto separate opinions endorsing the strong reading of this doctrine. The newest justice, Amy Coney Barrett, may well agree. And Chief Justice John Roberts, while not agreeing it was appropriate to apply this doctrine in these pre-election cases, was the lead dissenter in a 2015 case out of Arizona advancing a similar theory about broad legislative power to set the rules for federal elections.

Either in the Pennsylvania case or in another, the court’s conservative majority could soon embrace a strong version of the independent state legislature doctrine. This could take state courts out of their essential role in protecting voting rights. It could potentially eliminate the ability of voters to use ballot measures to enact nonpartisan redistricting reform and other measures that apply to federal elections. It could give conservative courts looking for an excuse a reason to scuttle voter-protective rules enacted by state election boards.

Together, the Trump-related precedents mean that neither state nor federal courts are likely to be able to play a backstop role when Republican state legislatures pass new restrictive voting laws, and that efforts to get around these state legislative efforts are likely to fail as well. Although in theory Congress has the power to override state legislatures with voter-protective legislation for federal elections, it is hard to see any of that getting through the next Congress even if Democrats barely grab control by winning the upcoming pair of Senate runoffs in Georgia.

Mr. Trump has not admitted it, but he lost the 2020 election. His attack on voting rights and the legitimacy of our election system, however, will live far beyond his presidency. At stake is whether this country continues to adhere to the rule of law and to allow elections to be decided by a majority of voters.