Explanation: in all English-speaking world Catholicism is under suspicion because Catholicism (already in times of Henry VIII and Elizabeth I) was associated with imperial ambitions of papacy and Rome (i.e. Rome could be easily acused of hypocrisy because it declared itself as a representant of spiritual power taking care of salvation of souls of all the Christians but at the same time strived for political power and material wealth). In the US there was legitimate fear that Catholics recognize the only authority: that of Rome and not that of Constitution. Especially conservatives are dangerous because they believe in "Omnia potestas a Deo" (all power belongs to God).
