In 2005 in McCreary County v. ACLU, Sandra Day O’Connor tendered the decisive vote to hold unconstitutional a Kentucky courthouse’s Ten Commandments display, she asks: “Those who would renegotiate the boundaries between church and state must therefore answer a difficult question: Why would we trade a system that has served us so well for one that has served others so poorly?��� She introduced the “endorsement test,” which reinforced the establishment clause principle that the government may not support a particular religious viewpoint and, instead, must endeavor to be neutral toward religion. Source: scotusblog.com