5 controversial voting laws in the US, from Minnesota's vouching system to noncitizen voting

As Americans head to the polls to cast their ballots in the midterm elections, questions of election integrity loom amid concerns over illegal immigration, ballot harvesting and alleged rampant voter fraud that has drawn the attention of the U.S. Department of Justice.

Federal law dictates a nationwide set of eligibility rules, anti-discrimination protections and certain administrative requirements for elections, though most day-to-day election administration is left to the states. Provided they don't violate the constitutional or statutory rules, details such as ID requirements, early or mail-in voting, registration deadlines and felon voting rights can vary widely.

Here are five unusual or controversial voting laws from various U.S. states and municipalities, some of which have drawn sharp criticism.