The brief flirtation with bringing mobile voting to D.C. has come to an end.

The author of a bill introduced earlier this year that would have allowed D.C. residents to cast ballots from their phone or tablet says she will not pursue the idea next year, effectively killing the dream of Bradley Tusk, a well-connected venture capitalist and philanthropist, to make the city the first jurisdiction in the U.S. to fully implement mobile voting.

D.C. Councilmember Brooke Pinto (D-Ward 2) brought the bill to the council. “Since introducing the bill, I have had many more conversations with residents and experts and my staff and I have read additional reporting on the issue. At this time, mobile voting is not ripe to move forward as additional security protections are likely needed to be considered in the event we do adopt a mobile voting option in the future,” she wrote in an email.

Pinto introduced the mobile voting bill in February, building off a campaign Tusk launched last year to push mobile voting in jurisdictions across the country — starting with the District. Tusk and Pinto said that mobile voting would increase turnout and democratic engagement by making it easier for residents to vote, especially Black and Latino voters for whom turnout rates tend to lag behind white voters in the city.

“When voting rights are under attack around the country, I am proud of the steps my colleagues and I have taken to make voting more accessible in D.C.,” said Pinto. “The mobile voting bill that I introduced aimed to do just that — make voting more accessible to more District residents, many of whom are underrepresented in elections.”

But the bill quickly raised alarms among many cybersecurity experts, who said there are too many remaining risks to pursue mobile voting at scale at this point. And those same arguments were highlighted in a new assessment this month from a working group organized by the Center for Security in Politics at the University of California at Berkeley and paid for by Tusk. In their report, 13 experts on elections management and cybersecurity determined that while mobile voting holds promise, “the current cybersecurity environment and state of technology make it infeasible… to draft responsible standards to support the use of internet ballot return in U.S. public elections at this time.”

This week, a coalition of organizations, including Public Citizen and the Center for Democracy and Technology, wrote lawmakers and urged them to hold off on any future mobile voting bills until broader questions of cybersecurity could be addressed. “No bill that would enable online voting — specifically, the electronic return of voted ballots — should be considered until election experts agree that such a system would be both secure and reliable for D.C. voters,” they wrote.

Pinto’s bill had already faced opposition on the council and wasn’t set to move the proposal forward this year, but her change of heart on the current safety of mobile voting means that Tusk’s venture isn’t expected to gain much, if any, steam next year. In an emailed statement, though, Tusk said he would continue working towards making mobile voting a reality.

“Here’s what we know: Too many Americans are left out of the electoral process at the moment, and we need to identify approaches like mobile voting that reduce barriers to the vote. That’s why we are funding the development of more secure technology for mobile voting that addresses the challenges the working group identified. We have just released a detailed new architectural overview and data flow of this system that our grantees are developing. Our goal is to release the system publicly in 2023 for thorough public security testing along with usability and accessibility assessments to ensure it meets the needs of voters and standards of election officials,” he said.

The experts organized by the Center for Security in Politics didn’t fully close the door on mobile voting being possible in the future.

“There is promise, however, as technological developments have moved us closer to using internet ballot return in a secure and accessible way. Still, additional progress is necessary before standards might be developed to support the widespread use of internet ballot return in U.S. public elections, and overall cybersecurity continues to face monumental challenges,” they wrote.

D.C. has taken other steps in recent to broaden voting accessibility, largely by mailing every registered voter a ballot, which will now become a permanent feature of elections moving forward.

This post was updated with a statement from Bradley Tusk.