It's amazing how many Catholics, and Jews are colossal libs. If you look at their tenets, and dogma, it's very conservative. But, I guess that's why there is the term cafeteria catholic. Is there a comparable term for Jews, like deli jew ?
Honestly, there is room for good Catholics on the left of center. Pro-life is supposed to be non-negotiable. What happened was that the US. Conference of Bishops in the 1960s and 1970s focused on "social justice" issues: poverty, etc. There are many Catholics who go to church with me every week who believe that it is our duty as a society to provide for the poor, and many U.S. bishops agree.
Where the trouble begins, however, is that many Catholics look at the social justice issues as of equal importance to the life issues, which they are not. Good Catholics can disagree on Ryan's budget, for example, but there can be no disagreement about the sacredness of human life.
Multiply these issues with the fact that many Catholics are ignorant of their faith, church attendance has plummetted because of the religious scandals, the fact that many seminaries were lefrowing hotbeds through the 1970s and 1908s, and you have the situation where many Cahtolics just don't get it.
Also, since the time of St. Peter, bishops have made terrible politicans. Look at how many worked in the 1960s and 1970s with Central American communists to feed the poor. When the communists got power, lots were killed at Mass.