One more point.  The Pew referenced study has this to say about Catholics attitude toward abortion:  "...among Catholics, 53% say abortion should be legal in all or most cases and 44% say it should be illegal."  This is not far off the general survey results that 57% of adults believe abortion should be legal in all or most cases and 40% say it should be illegal in all or most cases.  In 20 years, the approximate 60/40 split has wiggled up and down a bit but not really changed.