Likewise I really doubt that many Catholic to Mainline Christians are country club Republicans like the stereotype might suggest.
Catholic-to-mainline converts? Who converts to mainline Protestant denominations these days?
(Other than perhaps some more liberal-minded Catholics, I think that mainline Protestants converting to Catholicism is more of a thing. For example, many of the Episcopalians who value the Catholic aspects of traditional Anglican doctrine and practice would be among that group, just as many of the Episcopalians who value the Protestant aspects of traditional Anglican doctrine and practice convert to Evangelical and/or non-Evangelical traditional and confessional Protestant groups. And both of these groups within the Episcopal Church are often politically and socially conservative. Hence, why so many of them are leaving the denomination.
).