MUSCATINE, Iowa — Like many voters in Iowa, Ben Hoopes has been listening closely to all the tough talk about illegal immigration coming from the Republican presidential candidates who have crisscrossed his state every week.

There was Donald J. Trump’s plan to build an impenetrable wall across the border and force Mexico to share the cost. Gov. Bobby Jindal of Louisiana said that immigrants who do not fully integrate and learn English are guilty of “invasion.” Chris Christie, the New Jersey governor, last weekend suggested tracking new immigrants like human FedEx packages.

Mr. Hoopes, 33, a salesman and Republican voter in Muscatine, believes something needs to be done about unauthorized workers in Iowa, so he welcomes the attention to the issue. But he worries: Are the candidates telling the crowds only what they want to hear? Is a complicated issue becoming oversimplified?

“It’s just a show right now,” Mr. Hoopes said, pausing from his job at a carpet store downtown. “I heard today that Scott Walker might want to build a wall on the Canadian border. I didn’t realize illegal Canadian immigration was such a big problem.”