Legal basis
Congress passed the Uniformed and Overseas Citizens Voting Act (UOCAVA)in 1986. This law provides a legal mechanism for absentee voting by eligible members of the military, other government agencies, and civilians permanently living abroad. UOCAVA voting is administered by the Federal Voting Assistance Program(FVAP), an agency within the Department of Defense (DOD). Although FVAP provides services for military members and civilians alike, its location underscores the military aspect of the general population covered by UOCAVA.
Congress passed the Military and Overseas Voter Empowerment (MOVE) Actin 2009 to provide further support to UOCAVA voters. The MOVE Act requires states to accept electronic voter registration for potential UOCAVA voters, along with requiring voting assistance offices on military installations. The MOVE Act also requires all states to send ballots to UOCAVA voters at least 45 days prior to an election.
In addition to UOCAVA and MOVE, parts of the National Voting Rights (NVRA)and Help America Vote (HAVA)Acts also apply to the potential overseas and military voter. Under the NVRA, the DOD is required to implement voter registration procedures not unlike those used by ordinary citizens at state motor vehicle bureaus. Following the passage of HAVA, the DOD was also required to perform other functions similar to states' responsibilities to provide information to voters about deadlines and registration processes. HAVA also mandated a more uniform application of UOCAVA requirements across all states.
Who are UOCAVA voters?
It is not always easy to define the various groups that make up the UOCAVA population because not all UOCAVA voters register or vote using the provisions of the law that apply specifically to them. The 1986 law applies to all active duty members of the military, members of the Merchant Marine, the commissioned corps of the Public Health Service and the National Oceanic and Atmospheric Administration, family members of these groups, and regular civilians residing abroad. However, if UOCAVA voters use traditional methods to register and vote, they are counted among the general population and not captured by any administrative assessments aimed specifically at measuring the UOCAVA population.
More broadly, the UOCAVA population can be segmented into its two largest subpopulations: the active duty military and civilians living abroad. It is surprisingly difficult to estimate how many people are covered under UOCAVA, especially when it comes to civilians living abroad. Recent researchsuggests that altogether, these groups totaled around 3.9 million eligible voters, with 2.6 million of those being overseas civilians. This creates a voting-eligible population comparable to that of Colorado.
Registration and voting
UOCAVA voters must be registered to vote in a given state or territory like any other US voter. They do, however, have methods of registration available that ordinary citizens do not. The Federal Post Card Application (FPCA)allows UOCAVA citizens to register to vote, request ballots, and update their contact information with their local election office from afar.
UOCAVA voters have several methods by which they can cast ballots. Military voters living in their state of residence and near the polling location can vote in person like any other registered voter, or by regular absentee ballot pursuant to the laws of the state in which they are registered. States also have specific mechanisms in place for receiving requests and transmitting ballots to potential UOCAVA voters. FVAP provides an online toolto help facilitate this process for all states and eligible territories.
In addition, UOCAVA voters can also use the Federal Write-in Ballot (FWAB). The FWAB, much like the FPCA, serves as a backup mechanism for UOCAVA voters. Instead of using a more standardized absentee ballot, UOCAVA voters can use the FWAB form to vote by write-in, although certain restrictions still apply and vary by state.
Trends in UOCAVA voting
Voting by the UOCAVA population can be tracked using data from the Election Administration and Voting Survey conducted by the Election Assistance Commission (EAC). Although not all states report their data to the EAC, it is possible to discern several important trends in recent years (see figure below). Perhaps the most important is the reduction of rejected ballots as the ratio of ballots returned and counted has achieved relative parity in recent elections.
Voter turnout among overseas civilians is quite low. Estimates suggest that over the past few elections less than 6% of this population voted, although the numbers were up in 2016. It is unclear whether changes in voting rates for these voters is due to politics or issues of administration, but as the figure above demonstrates, administrative issues have diminished in recent years.
As part of their legal mandate, FVAP is required to report to Congress (see here for the most recent post-election version) on the effectiveness of the program. This effort includes a series of post-election surveys asking members of the military about their registration and voting histories. According to the survey, self-reported voter turnout among the military has been generally comparable to that of the general civilian population, although in 2016 the rate fell to about 46%. This was around 13% less than was reported in 2012, and lower (by about the same amount) than the rate for the general population in 2016. It is unclear to what extent the traditional problems associated with self-reported voting also apply to the military, but there is little reason to think they are not equally applicable. The figure below shows the turnout level of the active-duty military (computed by FVAP Reports) compared with self-reported turnout on the Current Population Study's Voting and Registration Supplement and voting-eligible population turnout as calculated by the United States Elections Project.
Politically, UOCAVA citizens are as varied in their attitudes and preferences as any other segment of the broader voting population. Some researchsuggests that enlisted members of military are less likely to be strong partisans than their civilian counterparts, while officers tend to lean more Republican than Democrat. It should be noted, however, that political studies of the military population are rare and should be taken with the caveat that this group is difficult to sample and mostly shielded from traditional survey efforts. Representative data on overseas civilians is even rarer, although qualitative assessments suggest this population tends to prefer Democratic candidates.