The opposition candidate who is challenging Venezuelan President Nicolás Maduro has a simple pitch. Vote for us, Edmundo González says, and your loved ones can come home.

       But U.S. officials are wary of what might happen if Maduro is not defeated.

       More than 7 million Venezuelans — about a quarter of the population — have already fled Maduro’s authoritarian rule in the past decade. Of those who remain, more than 1 in 3 tell pollsters that if Maduro remains president after the July 28 vote, they’ll consider leaving the country themselves.