Linda Graham is a public figure. If he does something inexcusable, like calling a fellow Republican a “jackass”, he needs to hear from the people how low that was. Giving out his office number is useless - his staff answers it, not him. Emailing him is useless - he will never personally read them. Giving out his cell number was the best avenue for the folks to let Linda know how much they don’t like people who back stab their fellow Republicans. While he will only actually take a handful of the calls, at least he will know that such crap talk has consequences.
Your argument is that the morality of the means is unimportant, only the morality of the ends. We say that it is wrong when liberals reveal the personal information of conservatives in order to hurt the conservatives, but here, it's okay, because we don't like Graham. That is a fundamentally leftist argument. I ain't buying.
sitetest
Graham will know what the people think. But he still won’t care.