I'm not so sure I agree with this. I attend a large evangelical church that has a significant percentage of its members who are former Catholics (including, for what it's worth, my wife). I've spoken with a number of people about this, and I've not heard one person say that he left the Catholic church for political reasons. This is anecdotal, of course, but I don't think that your position is necessarily representative of all the ex-Catholics out there. The study presented in the article backs that up.
I'm speaking not of political liberalism, but of religious liberalism. And yes, that's what's done the damage over the last 40 years.
The people who invented "clown masses" weren't religious conservatives.