President Donald Trump's "tweet-egations" about massive voter fraud -- claiming that about 1 in 40 ballots were fraudulently cast in last year's presidential election -- are as well known as they've been thoroughly debunked. An extensive post-election inquiry of state election officials did find a few scattered examples of suspect ballots, but on a scale closer to 1 in 1 million. And most of those ballots were likely cast by mistake, not with fraudulent intent.

As former secretaries of state -- an elected Democrat from Oregon and an elected Republican from Washington state -- we were responsible for our states' elections. We worked closely with our respective states' election administrators (also of both parties), and we know what an outstanding job these officials and their staffs do to ensure the integrity of our election process. We're convinced that true voter fraud is exceedingly rare and almost always inconsequential. However, there is one problem with our election systems that does deserve more of our collective attention: the inordinate number of outdated and duplicative voter-registration records.

A study by the Pew Center on the States in 2012 estimated than 1 in every 8 voter registrations -- about 24 million across the 50 states and the District of Columbia -- were invalid or inaccurate. This included almost 3 million people with active registration in more than one state. On the surface, these statistics instantly conjure up a potential problem of staggering -- even Trumpian-- proportions. But as David Becker, who oversaw the study for Pew, noted at the time, "These bad records are not leading to fraud but could lead to the perception of fraud."

Election officials like us have long been aware of this problem. We also know that voters themselves hardly ever know of such outdated or duplicate records, much less feel the least bit tempted to risk a felony prison term to cast an inconsequential extra vote or two. But it's important to understand why so many voting records aren't current.

America is a highly mobile society. Census data suggest that in any given year, about 12 percent of Americans will change their physical addresses. For 18-to-34-year-olds, the number is closer to 25 percent.

The freedom to travel or relocate without being required to inform government authorities or cancel an existing voter-registration record is widely viewed as a basic right. And election laws generally allow citizens to physically move, even for prolonged periods, and still consider a former address as their official home address for voting purposes. Career military personnel, students going to college and businesspeople temporarily re-assigned to another city are just three examples of this. What citizens can't do, without risking imprisonment, is intentionally register in order to vote in multiple jurisdictions.

Every election cycle, state and local election officials must work with limited resources -- often along with poorly devised election laws imposed on them by state legislators -- to wrestle with these realities. They routinely use Social Security death records to trim their voting roles, for example, and they're constantly processing new and updated registration forms from voters. But sometimes even well intentioned attempts to update voter rolls go awry, as when 120,000 New York City voters were inadvertently purged from the rolls just prior to the April 2016 presidential primary.

As incidents like that make clear, election officials need more and better tools to help ensure that their records are accurate. One obvious step would be for a lot more states to join ERIC, an entity created by a group of states in the wake of Pew's 2012 report. Through ERIC, 20 states and D.C. now share their voting records to help eliminate duplicate and outdated records, and those states' rolls have improved considerably.

Another reform would be to allow election officials in every state to automatically update a voter-registration record when a voter informs the U.S. Postal Service or another government agency of a new address. Oregon and Washington state both routinely do this, as do more than a dozen other states. And while a 1993 law passed by Congress requires such automatic updates when voters report address changes to their DMV offices, a recent study by Project Vote asserted that most states are still non-compliant.

Our two states' "vote at home" systems, in which all registered voters are mailed their ballots to their official addresses at least two weeks prior to Election Day, also foster far more accurate voting rolls. Non-forwardable ballots, when returned with Postal Service change-of-address stickers, cause our election officials to automatically update registration records for the next election.

Contrast this with Michigan, where outdated rolls sometimes show more registered voters than voting-eligible citizens. Did that absent Detroit voter stay home with the flu, or leave two years ago for a job in Arizona? Simply failing to show up on Election Day for a school board election doesn't provide a determinative answer either way.

Given our sophisticated technology and ubiquitous government databases, there's no good reason our voting records can't be far more accurate. It's long past time that policymakers -- especially state legislators -- gave local election officials the tools and resources they need to dramatically improve this situation. And if the new voter-fraud commission announced by President Trump, to be led by Vice President Mike Pence and Kansas Secretary of State Kris Kobach, wants to deal honestly with the real threat to the integrity of our elections, this is an issue that should be high on its agenda.