"pro life" is a pretty hard (and exploitive) line separating the two
E.g. get someone fervently believing that their vote is critical to preventing "murder of children", and you can abuse them economically however the hell you want - they'll hate you but they'll still vote for you because the other guy "murders children". This one is such an oldie but goodie that each party has crafted its own wedge issue around it: abortion for Republicans, guns for Democrats.