Complex sentence: After Roe v. Wade, the involvement of the Catholic hierarchy in American politics increased to an unprecedented level, with bishops devoting more time, energy and money to the issue of abortion than any other single issue.
Split into simpler sentences: After Roe v. Wade, the involvement of the Catholic hierarchy increased to an unprecedented level. Curran asserts that, since Roe v. Wade, the Catholic hierarchy in the U.S. has devoted more time, energy and money to the issue of abortion than any other single issue.