Fact-Checking DHS Secretary Mullin's Claim That Foreign Adversaries Can 'Change Your Vote'

On July 17, 2026, Department of Homeland Security Secretary Markwayne Mullin delivered a stark warning regarding U.S. election infrastructure, claiming that foreign adversaries possess "vital pieces" of American voting machines and can directly alter ballots.[1][3]

Speaking at a press conference, Mullin stated that hostile nations have access to "what they consider the key to the back" of voting systems. "We know that they can change voter registration, and your vote," he said. "We know it's possible. There's not a question. It's not even for debate."[2][5]

The assertions come as the Trump administration pushes states to adopt new federal security enhancements and participate in the Systematic Alien Verification for Entitlements (SAVE) program to scrub voter rolls, with Mullin claiming DHS has identified 250,000 noncitizens registered across four states. Mullin warned that states refusing to comply could lose federal election grants or face prosecution.[4][5][6]

Evaluating these claims requires separating the theoretical risks of election technology from the documented history of foreign interference. Computer scientists, intelligence agencies, and state election officials offer a nuanced view of where the actual vulnerabilities lie and how they are mitigated.[1][2]

The global nature of electronics manufacturing means that hardware components in voting machines—such as memory chips, processors, and touchscreens—are often sourced internationally. Security experts have long warned about these supply chain vulnerabilities.[1][2]

If a foreign adversary intercepts or compromises a component during the manufacturing process, they could theoretically introduce malicious code or hardware backdoors before the machine ever reaches a U.S. polling place.[1][2]

J. Alex Halderman, a University of Michigan computer science professor who studies voting systems, confirmed to fact-checkers that weaknesses exist that could allow adversaries to tamper with hardware and bypass security controls.[1][2]

However, while the hardware vulnerabilities are real, the leap to active vote-flipping requires overcoming significant operational hurdles. A 2024 National Intelligence Council assessment highlighted that U.S. voting machines are typically not connected to the internet or to each other.[1][3]

To exploit a hardware vulnerability, an attacker would generally need physical access to the machine or a highly sophisticated, pre-programmed supply chain attack that triggers on election day without being detected during pre-election logic and accuracy testing.[1][2]

Furthermore, over the past decade, the vast majority of U.S. jurisdictions have transitioned to systems that produce a voter-verified paper audit trail (VVPAT). Even if a machine's software were compromised to flip digital tallies, post-election audits comparing the digital results to the physical paper ballots would detect the discrepancy.[2][3]

Despite the known vulnerabilities, there is no public evidence that foreign actors have successfully altered votes in a U.S. election. Halderman noted that "the existence of vulnerabilities does not mean those vulnerabilities will imminently be exploited."[1][2]

A comprehensive 2021 report by federal intelligence agencies concluded there was no proof of foreign actors manipulating the voting process or tallying in the 2020 election. The agencies assessed that any large-scale attempt to do so would likely be detected by physical security and cyber monitoring.[1][2]

Fact-checkers also highlighted a technical inaccuracy in Mullin's statement linking voting machines to voter registration. The process of registering to vote and maintaining voter rolls does not involve voting machines.[1][2]

Voter registration databases are maintained on state or county servers and are entirely distinct from the offline machines used to cast ballots. While voter registration databases are connected to the internet and have been targeted by foreign hackers in the past, compromising a voting machine does not grant access to registration rolls.[1][2]

When pressed for specific evidence of the hardware compromises Mullin referenced, the DHS referred inquiries to the White House, which reiterated the need for states to guard against noncitizen voting and secure their infrastructure.[1][2]

The DHS directives have sparked immediate resistance from several state leaders. Officials in states like California, Nevada, and New Jersey have defended their existing security protocols and pushed back against federal demands for voter data.[3][4]

Election administration in the United States is highly decentralized, managed by thousands of state and local jurisdictions rather than a single federal body. Mullin's threat to withhold funding or pursue legal action represents a significant escalation in federal efforts to oversee state election processes.[3][4]

As the 2026 midterm elections approach, the debate over election security remains highly polarized. While experts advocate for continued funding to replace aging machines and expand rigorous post-election audits, they caution against rhetoric that may inadvertently undermine public confidence in the layered defenses already in place.[1][3]