"We were just asking questions" is going to be their defense.
They know that misrepresenting themselves as people in positions of power are going to scare the shit out of people into answering questions, and they know that specifically targeting people who are undocumented is going to get them to say whatever to get them to go away.
Voter fraud isn't a problem because the amount of fraud you would have to do would be easily discovered. But what the Republicans are doing is election fraud. It's way easier to prevent individuals from voting than it is to manufacture votes. All these voter protection bills do is prevent actual us citizens from voting.