Three people were charged with felony election misconduct in Council Bluffs last week following an investigation by the Iowa Division of Criminal Investigation that alleged each of the three had voted in Iowa despite not being American citizens.

The division’s investigation coincides with a push from Iowa Secretary of State Matt Schultz to crack down on fraudulent voting statewide. Schultz claimed in March to have discovered that more than 1,200 foreign nationals had voted improperly in the 2010 general election.

He subsequently implemented two emergency voting rules requiring Iowa voter rolls to be crosschecked against state and federal databases in order to weed out ineligible voters.

The American Civil Liberties Union and the League of United Latin American Citizens of Iowa are suing to block the implementation of those rules on the grounds that they could potentially erase legal voters from the rolls, as was the case when a similar law was put in place in Florida earlier this year.

The DCI’s investigation of voter fraud is moving forward. And while the Council Bluffs investigation seems to have borne fruit, it is much easier to charge people with voter fraud than it is to convict them.

Under Iowa law, prosecutors have to prove that those charged with fraud voted despite knowing that they were not eligible. Based on the formal complaints issued against the three individuals in question — two Canadian citizens and a Mexican citizen, all legally residing in the United States — none of the accused knew they were violating the law by voting.

This issue creates something of a moral gray area in the voter-fraud debate. If we can’t prove that foreign nationals who vote are doing so with malicious intent, can we legitimately use the specter of voter fraud to justify emergency voting rules that carry at least some risk of disenfranchising legal voters?

How many votes cast by foreign nationals are acceptable, if there’s no evidence that they intend to pervert our democracy? How many of these voters would have to be caught in order to legitimize the threat that legal voters could be booted from the rolls with only a few weeks until election day?

Illegal voting is a problem that should be addressed in due course, but it’s not an existential threat that requires a shock-and-awe solution and the accompanying collateral damage.