With less than six weeks until Election Day, laws governing how Americans vote remain in flux in many battleground states, with the two parties locked in an intensive fight over the rules as President Trump continues to suggest he will challenge any outcome unfavorable to him.
The combination of the pandemic, doubts about the capacity of the Postal Service to handle a flood of mail ballots and an aggressive push by Democrats to expand access to voting rights and counter Republican efforts to limit them has fueled litigation and legislative battles across the country that have not been resolved even as early voting has gotten underway.
The result is uncertainty that Mr. Trump is already seizing on in his extraordinary campaign to cast doubt on the election system and the result. In the latest of a string of remarks on the issue, the president refused on Wednesday to commit to a peaceful transfer of power, igniting new concern about his commitment to the Constitution and drawing pushback on Thursday from prominent members of his party.
After the White House then said that Mr. Trump would accept the results of a “free and fair” election, the president weighed in again, saying that he was not sure the November election could be “honest” because mail-in ballots were “a whole big scam.”
Even before his comments over the past several days, the confusion surrounding how ballots should be cast and counted had reached a level rarely before seen.
In Wisconsin and Pennsylvania, two states pivotal to the outcome of the presidential race between Mr. Trump and Joseph R. Biden Jr., the Democratic nominee, there are legal fights underway that could affect when voters have to mail in their ballots. In Pennsylvania and Ohio, there are lawsuits about where voters might be able to drop off their ballots.
In those states and others, the very means by which the election will be conducted is still being hashed out through legislation, executive actions and consent decrees, as well as litigation.
In Michigan, legislation is pending concerning whether voters will have the ability to fix any problems with their mail-in ballots. In North Carolina, elections officials signed an agreement to extend the deadline for receiving mail ballots by six days, and Republicans immediately pledged to try to overturn it.
The problem has been exacerbated by the options that states have sought to provide to make voting safer and easier amid the pandemic, changes that have often been met with a flood of lawsuits.
“A whole bunch of Americans are going to have a different process than they may be used to,” said Justin Levitt, a professor at Loyola Law School who oversaw voting rights in the Obama administration as a deputy assistant attorney general. Mr. Levitt has been tracking pandemic-related election law cases across the country, and he said that “any change is inevitably going to lead to disruption.”
No state is more acutely aware of the potential for litigation-caused electoral chaos than Wisconsin. There, state elections and a presidential primary were held in early April during the first serious peak of the coronavirus, and were conducted amid a surge of lawsuits and rules changes that left voters confused. Many felt forced to brave hourslong lines at the few in-person voting centers in cities like Milwaukee and Green Bay to assure that their ballot would count.
Now, Wisconsin voters are staring down an almost identical situation. The same federal judge who was in the middle of one of the main cases litigated in the spring, William M. Conley, sided with Democrats in a ruling this week that ballots postmarked by Election Day could be counted if they were received as late as Nov. 9, six days later. But the judge ruled against Democrats in upholding a requirement that absentee voters have a signature from a witness.
Judge Conley issued a weeklong stay in his ruling, and Republicans filed notices of appeal on Wednesday, seeking to keep any ballots received after Election Day from being counted.
The uncertainty has forced the Wisconsin Elections Commission to plan for multiple regulations even as it sends out 2.7 million pieces of mail to voters with election information.
The legal maneuvering has proved difficult for some Wisconsin voters to track.
“I try to follow, but it’s hard to keep up,” said Paula Bullis, 50, from Washington, Wis., who has already mailed in her ballot but remains concerned about what will happen in November.
“I’m worried about the worst,” she said, “but I’m hopeful that the process and constitutional laws and the powers that be make it run smoothly.”
In Pennsylvania, Democrats and Republicans fought to a standstill in the General Assembly over elements of the rules for mail voting. The Republicans, who control both houses of the legislature, wanted to ban the use of drop boxes for completed ballots, in return for allowing election officials to begin processing absentee ballots before Election Day. (Democrats wanted to start 21 days before Election Day, and Republicans countered with three.)
But Republicans also knew Gov. Tom Wolf, a Democrat, would veto any bill they passed without Democratic support. And Democrats turned to the courts.
“We have a parallel path,” said Jay Costa, the Democratic leader in the Pennsylvania State Senate. “We have a series of court cases.”
This week, the Democrats notched a significant victory in the State Supreme Court, which extended the deadline for when ballots must be received by election officials and paved the way for more drop boxes to be installed.
But the court sided with the Republicans on two other issues: limiting efforts by other people and groups to collect completed ballots from voters — a practice denounced as “ballot harvesting” by Republicans who contend it can lead to fraud — and rejecting ballots that do not arrive with the required privacy envelope intact.
The ruling on the envelopes has led to dire predictions about the potential rejection of tens of thousands of what are being called naked ballots, leading to postelection chaos along the lines of the dispute over so-called hanging chads on Florida ballots that helped decide the 2000 presidential election.
The Trump campaign is seeking to ban drop boxes altogether in Pennsylvania, and a case on that issue is working its way through the federal courts. A judge put that lawsuit on hold to allow related cases to work their way through the state courts.
Election officials in Pennsylvania lamented the unsettled situation in a video message to voters, and warned that some deadlines may still change.
“There is a lot going on in the world of Pennsylvania elections,” said Julie Wheeler, a county commissioner in central Pennsylvania. “Ongoing lawsuits and legislative activity in Harrisburg may change some of these processes and deadlines, but if they do, we’ll be in touch with you as soon as possible to make sure all voters are aware of the changes, whether you’re planning to vote in person or to use a mail-in ballot.”
On Thursday, the Justice Department announced that it had opened an inquiry into “a small number of mail-in ballots” from military officials that had been discarded, a rare mid-investigation statement that threatened to further unnerve those voting by mail.
Some Pennsylvania voters have been dismayed at the back-and-forth and are opting to vote as they always have rather than trust a new voting system.
Denis Lawler, 72, said he was planning to vote on Election Day in Philadelphia “to make sure my vote will be counted.”
But he is growing increasingly uneasy about what will follow.
“It was one thing to have hanging chads in Florida,” Mr. Lawler said. “But now there are so many different issues being raised in so many different states that you could see, unless there is an overwhelming winner, you could see that there might be a lot of delay caused by lawsuits.”
In Ohio, the battle over drop boxes has been even more perplexing. The secretary of state, Frank LaRose, a Republican, ruled this month that each county may have only one drop-off location for ballots, saying he was constrained by existing law from expanding the number of sites.
A court had issued an opinion this month saying there was no one-box-per-county restriction. But Mr. LaRose said that, since it was just an opinion, and not an injunction, he saw no reason to reverse his original decision.
Republicans have appealed the judge’s opinion, and a lawsuit from state Democrats is still pending, but time is running short to install new drop boxes.
“Having these things in place in October is critical obviously,” said David Pepper, the chairman of the Ohio Democratic Party. “Right now, if you mail a ballot application or if you go to the drop box, it’s going to get there.”
The drop boxes, he noted, would be needed in the final 10 days of the election.
Election experts concur that time is running out to settle these disputes.
“We are past the point in time where voter-facing changes can be implemented effectively,” said David Becker, the founder and executive director of the Center for Election Innovation and Research, a group created to help election administrators.
While Mr. Becker said he favored changes to expand access to voting, he said that “there are good changes that if implemented too late can have a negative impact” and that confusion among voters “is a very real thing that has a cost.”
Traditionally, the likelihood of lawsuits resulting in rulings that order significant changes has diminished as Election Day approaches, with courts generally weighing the potential for disruption as a factor in their decisions.
But Wisconsin’s election in April proved an exception, with the Supreme Court issuing a ruling that changed deadlines on the eve of the election.
The Democratic National Committee and the Republican National Committee have had more money to spend on lawsuits because of a change in campaign finance laws quietly slipped into a spending bill in 2014 that allowed them to raise an extra $97,400 per donor for legal costs.
That provision was drafted in large part by Marc Elias, a leading Democratic election lawyer who has brought a range of lawsuits this year seeking to loosen voting regulations in several states on behalf of the Democratic National Committee and other groups, including Priorities USA, the leading super PAC devoted to supporting Mr. Biden’s campaign.
Mr. Elias also created a group this year called Democracy Docket Action Fund that says it is raising money for voting rights lawsuits.
The Trump campaign, sometimes in concert with the Republican National Committee and its state affiliates, has gone to court to try to block changes sought by Democrats and to challenge new rules expanding access to mail-in voting and moving back ballot deadlines.
Republican Party committees have intervened in a number of the cases opposing the Democratic challenges, sometimes with support from conservative nonprofit groups including Honest Elections Project, which has spent hundreds of thousands of dollars on advertisements denouncing mail-in voting as a “brazen attempt to manipulate the election system for partisan advantage.”
For some election experts, the extended uncertainty underscores the fragility of the greatly decentralized American electoral system, something Mr. Trump and his allies seem to be suggesting they could exploit in any postelection litigation about the outcome.
“Even without this explosion, there’s been a continued growth of litigation over election rules because, in part, we don’t have a baseline set of a federal guarantee of voter access,” said Wendy R. Weiser, the director of the Democracy Program at the Brennan Center for Justice.