The alignment between Catholics and Protestants in US politics is a relatively recent phenomenon. Up through the 70s, Protestant groups were generally anti-Catholic (something that was a factor when Kennedy ran). The KKK was anti-Catholic. Prejudice against Catholics, who were often suspected of having more loyalty to the Pope than the country, was pretty constant throughout US history.

That started to change in the 80s. The Southern Baptist Convention, which was controlled by moderates at the time, had originally supported the Roe decision. Catholics, on the other hand, were against abortion and birth control (and also largely against the death penalty). When the federal government started to demand that Baptist colleges start to admit black students, that all changed. Abortion became the wedge issue of choice. Conservative Catholics leaned into the shift, with growing political power fueled by donations to Catholic lobby organizations and by the creation of JPII as a charismatic media star.

As a former Catholic and a strong atheist, I have absolutely no love for the Catholic Church. I do, however, believe that Francis is sincere in his beliefs and attempts to reform things. I suspect that the next pope is going to make Ratzinger look like a hippie - they’re going to become ultra-conservative. But for now, as a member of Team Rainbow, I really do appreciate what he’s trying to do. And if it can break off even a portion of the Catholic vote, so much the better.