Pick up the book
"Defenders of the Unborn."
The quick answer is that social changes both inside and outside the Church created a divide among though who remained in the Church–whose faith wasn’t entirely shaken. Democrats began rejecting socially conservative sexual norms and began abandoning the Pro Life cause. Republicans began taking up social conservativism, using the promise to overturn Roe as a way to move a good chunk of the Democratic vote to the Republican Party.
For four decades, single issue voting has lead to lending more of an ear to Republican rhetoric. As such, they buy into it more. They become more loyal Catholic republicans then merely the single issue voters who were moved into voting this way to achieve one end. But they–as we saw with the election of trump–will still get desperate enough to shame those not on the full Republican bandwagon to believe they have a moral duty to vote Republican.
I don’t think it helps either that liberal Catholicism is an idealogy that has major problems. It’s most visible when you look at liberal liturgical abuses. But we often demonizes valid points, failing to see the errors of the traditionalists and the conservatives.
It’s actually for this reason, I’ve liked Pope Francis. The traditionalists have very valid points about the liturgy. The liberals have valid points about clericalism. The solution there is to recognize the laity’s role in the Mass, to rediscover it. The desire to simply give the laity the job of the choir and altar servers denies the role the laity once had. Perhaps that it because it was never spoken about.
And when it comes to Church teaching, we need to look at it’s actual wisdom, not freak out when it develops, not put an agenda against it. We need to embrace all of it, including social justice issues. The whole life movement is not identical to what the seamless garment was in the early 80s.
All these things come only through not becoming too in love with our own ideas, but recognizing that we can fall into great error and still make great points. And the Holy Spirit’s job is to guide that discussion. But so long as we fear each other entirely, and see our brother as our enemy, we impede that dialogue.
Chesteron said the business of progressives was to go on making mistakes. The business of conservatives is to prevent mistakes from being corrected. The hard part is realizing there isn’t a perfect parish that balances these things.