Voting technology

Mechanical Lever Voting Machines

Mechanical lever voting machines emerged in the 1890s and allowed voters to indicate their choice by depressing a lever next to the preferred candidate. As shown below, mechanical lever machines were kept inside voting booths, concealed by a retractable curtain to ensure privacy. Machines often contained an interlocking mechanism that prevented the voter from selecting more candidates than allowed for that contest, also known as overvoting. Once the voter finished marking their ballot, they pulled the large lever again, which incremented the counters for their choices and prepared the machine for the next voter. At the end of Election Day, votes were counted by opening the machine and reading the numbers on the counters associated with all the candidates. 

Punch-Card Voting Machines

Punch-card voting devices were developed in the 1960s and relied on modified Hollerith cards — an early medium for storing digital data — to record votes. Voters most commonly operated them by inserting a blank pre-scored card into a holder. The holder contained a ballot and a set of targets associating each choice with a punch position on the card. Voters would vote for a candidate by using a stylus to dislodge a chad (the pre-scored bit of paper) and create a hole in the card associated with the candidate’s number. When the voter was done, they would take the ballot card and deposit it in a ballot box. At the end of Election Day, the ballots were counted using a card reader, usually in the central election office. 

Optical Scanners

Optical scanners were first used in the 1960s to help count paper ballots. Operationally, optical scanners differ significantly from mechanical lever voting machines and punch-card devices. The latter two devices are used to mark ballots directly, while optical scanners are used solely to tabulate ballots. Early optical scanners were essentially the same technology used to scan standardized tests. Today, however, optical scanners use advanced imaging technology to analyze ballots and tabulate votes, rather than relying solely upon light-sensor detection of ballot markings. This allows modern scanners to flag errors such as overvotes and, depending on the scanner, let voters correct them before casting their ballots.

In jurisdictions that use optical scanners, voters often mark a paper ballot in a private booth by darkening an oval, completing an arrow, or filling in a box for each selection on their ballot. In others, voters use a ballot marking device (BMD), which presents an electronic ballot on a screen and allows the voter to select contest options and verify the accuracy of their selections. The BMD then prints a paper copy of the voter’s ballot.

What happens after a voter has marked their paper ballot depends on whether ballots are counted by each precinct or at a central location. In jurisdictions where ballots are counted in precincts, an optical scanner is often connected to a ballot box (shown in the image provided above on the left). Voters feed their ballot into the optical scanner that reads their selections as the ballot is deposited into the ballot box. Precincts then count ballots at the end of Election Day by printing a tabulation report from the optical scanners. Precinct vote totals are then transferred, by paper or electronically, back to the central election office. 

In jurisdictions where ballots are scanned and tabulated at a central facility, ballots are placed in a ballot box (as shown in the image provided above on the right) and then securely transferred to a central counting facility at the end of Election Day. At these facilities, ballots are scanned by hand-fed or high-speed batch-fed optical scanners. Hand-fed scanners accept one ballot at a time, inserted manually by a voter or election official, while batch-fed scanners automatically draw ballots from a stack loaded into a feeder tray, allowing them to process ballots more efficiently. Officials at central count facilities can then print vote totals and report them to the proper election authority.

Direct-Recording Electronic Systems

Jurisdictions began to adopt Direct-Recording Electronic (DRE) systems in the 1970s. The earliest DREs were essentially electronic versions of mechanical lever machines, with push buttons replacing the levers and electrical storage devices replacing mechanical counters. However, modern DREs are essentially portable computers configured to display ballot choices and then record votes electronically. Touch screens are the most common way for voters to mark their ballots, although older systems still rely on push buttons. Once voters cast their ballots on a DRE, their selections are recorded directly into computer memory. DREs also increasingly include a paper record called a Voter-Verified Paper Audit Trail (VVPAT) that can be used to audit or conduct a recount. 

Despite the rise of mechanical lever machines at the turn of the twentieth century, hand-counted paper ballots remained common throughout the country. Improvements to ballot boxes and ballot design helped combat political manipulation and reduced voter confusion; however, hand-counting remained slow, costly, and subject to human error. Longer ballots also exacerbated these issues. Under American federalism, a single ballot can contain dozens of races, spanning federal, state, and local government offices. Moreover, Americans’ distrust of appointed officials led to an increasing number of elected offices on ballots. The desire to count ballots more accurately and efficiently led states to incorporate technology-supported systems into the voting process. 

By the 1980s, mechanical-lever machines and punch-card voting systems had come to dominate the election technology landscape. Mechanical lever voting machines were first introduced in the 1890s and helped make the voting process more accurate and efficient. For voters, these machines helped prevent overvotes and allowed them to cast their ballot in the same booth where they made their selections. For administrators, mechanical lever machines tallied votes throughout Election Day, allowing them to report the results of every contest shortly after the polls closed.

While mechanical lever voting machines transformed the voting process, maintenance was complex, and operating the lever was not accessible for people with physical disabilities. Many voters also found it difficult to verify their ballot selections because the only way to do so was to visually inspect the positions of the levers. Once the lever was depressed, there was also no recorded image or paper trail of the voter’s selections. Because of these and other challenges, jurisdictions gradually phased out mechanical lever machines in the late 1970s and 1980s in favor of punch-card voting machines, optical scanners, and DREs. The Help America Vote Act (HAVA) of 2002 effectively outlawed their use in federal elections.

Like mechanical lever machines, punch-card voting machines peaked in use in the 1980s and declined modestly until the 2000 presidential election. Compared to hand-counted paper ballots, punch-card machines allowed for faster ballot tabulation. Machines could tabulate punch-card ballots at a central office, improving ballot-counting speed and the reporting of results. Unlike mechanical lever machines, they also produced a physical record of voters’ selections that could be read by hand when necessary, including during recounts. 

Punch-card voting machines became embroiled in controversy during the 2000 presidential election when Florida election officials struggled to interpret voter selections during the statewide recount due to “hanging chads” that failed to separate from the punch cards correctly and other ballot artifacts. As a result, the public heavily scrutinized the outcome of the election in Florida, and jurisdictions nationwide began to aggressively phase out punch-card voting machines. Between the 2000 and 2004 presidential elections, their usage was cut in half, with HAVA effectively mandating the retirement of punch-card and mechanical-lever-machine systems.

By 2004, a patchwork of technology-assisted systems was used throughout the United States. Using federal funds from HAVA, many jurisdictions purchased optical scanners to help count paper ballots. Jurisdictions first used optical scanners in the 1960s, but by the 2000s, the technology had advanced significantly in terms of reliability and counting speed. Optical scan ballots also helped reduce ambiguity in determining voter intent—a significant concern for both administrators and the public following the Florida controversy in 2000. As seen in Figure 2, optical scanners are still widely used throughout the U.S. for tabulating mail ballots. Approximately 80% of jurisdictions utilize batch-fed optical scanners that process hundreds of mail ballots per minute in bulk.

Jurisdictions began to adopt Direct-Recording Electronic (DRE) systems largely during the same period as optical scanners, but their use stagnated in the late 2000s and remained well below that of optical scanners (see Figure 1). HAVA’s accessibility requirements heavily influenced state adoption of DREs in the early 2000s given that, at the time, they were one of few systems that allowed people with physical disabilities and those who are blind or visually impaired to vote privately and independently. Since 2008, state use of DREs has declined due to concerns regarding the role of computers in recording and tabulating votes, particularly DREs that do not produce a VVPAT. 

When analyzed alongside state election policy, geographic patterns in voting technology emerge. Figure 4 below shows the geographic distribution of by-mail/absentee voting policies throughout the United States. When viewed together, Figure 3 and Figure 4 show that paper ballots tabulated by optical scanners dominate the technology landscape in the western United States where by-mail voting is more common. While BMDs are often available for some voters, such as voters with disabilities, these jurisdictions primarily invest in batch-fed optical scanners given the need to process high volumes of mail ballots, rather than accommodate in-ballot marking. By contrast, DREs and hand-fed optical scanners are more common in states such as Indiana, Texas, South Carolina, Tennessee, and West Virginia where by-mail/absentee voting policies are more restrictive, and in-person voting is the primary means of casting a ballot. In other words, adoption of voting technologies has not only been influenced by federal funding and, historically, ballot length, but is also actively driven by state election policy.