The Republican Party has made voter fraud the red herring of this election. Now it turns out the party has been forced to cut its ties to a well-paid consulting firm after cases of real voter registration abuse arose in several swing states. A thorough federal investigation of the consulting firm, Strategic Allied Consulting, is needed.

Florida law enforcement officials said they were looking into “numerous” complaints against the company, which is run by Nathan Sproul, a well-known Republican campaign operative and former executive director of the Arizona Republican Party. Charges of registering dead people, altering and faking registrations and other abuses are being investigated in 10 Florida counties. Similar allegations of improprieties surfaced in recent months in Colorado and Nevada, while Virginia authorities last week charged a Republican registration supervisor and former Allied employee with destruction of voter registration forms by throwing them into a Dumpster.

The evidence of election chicanery prompted the Republican Party in September to sever its ties to Mr. Sproul’s registration operations, which had been hired in five states, including North Carolina, with an estimated $3 million in contracts. The company has denied any improper practices, contending that a few complaints would inevitably arise in its voluminous registration efforts in hundreds of jurisdictions. But authorities should look closely into the operations of Mr. Sproul’s various companies, which campaign records show have collected more than $17.6 million since 2004 from Republican committees, candidates and super PACs.

In a separate effort, Republican Party strategists have pushed many Republican-controlled statehouses to put in place constitutionally questionable voter ID laws to restrain Democratic-leaning voters. Studies show voter fraud is virtually nonexistent. Registration fraud, on the other hand, seems a growing area for abuse.