Get real - how many of these phone-in campaigns have there been? RINOs always cave.
This is why it has to be more than a simple call-in. It must be massive and widespread. Any and all who are able to show up at the Senator’s office with letters and petitions, go for it. Make it registered voters who have VOTED GOP last time, this in addition to e-mail and phone calls. Voter “walking lists” are available at County Auditors office. These identify those people.