I want to keep the Johnson Amendment on principle, but I wonder if its repeal would really help conservatives as much as conservatives seem to think it will. The religious right largely ignores legal prohibition that their churches endorse a candidate. Or at least they violate the spirit if not the letter of the law when they make it clear who they want to win and rile up their members to vote for their guy even if they never make an explicit endorsement. The fact that those religious organizations are regularly engaging in politics is why we have a concept of the "religious right."
But the funny truth is that all religious people are not the religious right. While they might think that "Christians" are their kind of Christians, there are a lot of religious groups with other perspectives. It is hardly clear to me that a majority of Christians are on the right. That's just the stereotype, a stereotype fostered by the Christian right's efforts to engage politically over the past few decades. If not just all Christians but all religions were no longer legally barred from engaging in outright campaigning, the Christian right might suddenly realize it is more of a minority than it suspected. Plus, all these other religious groups, minority religions that feel less courageous to buck the spirit of the Johnson Amendment already, would be free to engage politically in a more forceful way. A repeal won't just mean leftist churches would be able to engage in politics, mosques, synagogues, etc. would also be able to jump into the politics game.
Put another way, the Christian right's political capital is already being spent even under the Johnson Amendment. If that Amendment were repealed, the biggest change would be that other religious groups--groups that have not been trying to circumvent the Johnson Amendment--would finally be unshackled to oppose the religious right's agenda. The only reason the religious right is pushing for a repeal is because it thinks this is a Christian majority country (which is true), that they represent most Christians (which, I think, is false), and that there are enough of their kind of Christians to overwhelm other Christians plus members of other religions (which is definitely false).