Republican presidential candidate Donald Trump has been warning his supporters for weeks that the 2016 election is rigged.

It's a claim that Missouri Secretary of State Jason Kander calls "unfair" to local election authorities. The Illinois State Board of Election said in a statement that "allegations of a 'rigged' election are completely unfounded."

St. Louis Public Radio asked area election officials what keeps them up at night two weeks before a presidential contest. Here's what they said:

Erwin Switzer, chairman, St. Louis Board of Election Commissioners

"The big challenge is that we have an organization that has 25 full-time employees. And on Election Day, we have close to 1,000. So there's a lot of people who are not familiar with and used to all of the procedures that have to be followed."

Christian Tolbert, interim Republican director of elections, St. Louis County

"The biggest concern that I have is on the absentee end. Based on the court ruling in the Hubbard-Franks case, every absentee ballot has to be a paper ballot with an envelope. We're probably going to have 80,000 paper ballots that we have to process in a five-day window that the state allows. So we have to find staff above and beyond our current staff to help us out."

Eric Fey, Democratic director of elections, St. Louis County

"Everything. And I kind of mean that. There are so many moving parts to an election, and as a director you can't control every single piece of it. You just hope it all holds together and you make it through Election Day."

Rich Chrismer, director of elections, St. Charles County

"Nothing. We're prepared. We've been preparing for this November election since early last year. Preparation makes me feel comfortable about where we are and what we have to do to satisfy the opportunities we want to give our voters to come out and make their decision as they see fit."

Wes Wagner, county clerk, Jefferson County

"Parking. Most voters at this point sort of have an inclination if they're going to vote for Hillary Clinton or Donald Trump, but they're not prepared to see some of those issues on the back of the ballot. And those folks that have come into our office, it has taken them 20, 25 minute to vote. If voters are taking that length of time at a polling location, parking outside could be a factor, especially if you throw in eight or 10 poll workers, or two or three or four politicians out front handing out brochures."

Thomas Holbrook, county clerk, St. Clair County

"My biggest concern is with the enormous amount of volume, there's going to be delays. People today are used to driving through the drive-thru and getting their meal or soft drink or coffee in about one minute or two, and it just doesn't work that way when you're making sure that people are duly authorized to vote."

Deborah Ming-Mendoza, county clerk, Madison County

"I do not want any of our voters here in Madison County to be concerned about voter fraud, or people disrupting or causing chaos at the polling locations. I don't want them to be fearful of anything. I want them to turn out and vote. This is an important election at the top of the ballot all the way to the bottom of the ballot."

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