... and it was part of their religious belief. Therefore, their fleeing the jurisdiction of the United States was motivated by a religious conviction that had been made illegal, which makes them refugees in my understanding of the word.
“Persecution” sounds rather harsh, since they did return when Mexico went into revolution, though. I don’t agree with polygamy or plural marriage, but they believed themselves to be required to do so.
Trying to step out of my own existence, beliefs and biases for a moment, in order to try and understand, I suppose I’d want to flee the jurisdiction that tried to force me to divorce my wife, too. Well, wives, plural, and I don’t agree with that, but it’s likely the sentiment that Romney and others like him shared that motivated them to flee to Mexico.