Shapiro is a HUGE Zionist and has had problems in his office with sexual harassment (not by him, but his aides). With some saying he helped to cover it up.
He may play well in Pennsylvania, he does not play well in many states like Michigan and would not play well with the youth vote. The only real reason to pick Shapiro is for AIPAC money.
The prime Republican demographic is rich white christian men.
Voters that don't provide proof of citizenship are very likely to be poor. It's a hoop to jump through that's a lot harder when you don't have money, time, and a car.
I'll also point out that it's completely unnecessary as the great state of AZ has all the resources they'd need to go name by name and verify that these people are indeed citizens. Making them provide it during registration is a filler for the poor.
Much like literacy tests were there to filter out black people.