PHILADELPHIA — A local Republican Party in Southwestern Pennsylvania has a quote attributed to Samuel Adams on its website: “It does not take a majority to prevail … but rather an irate, tireless minority, keen on setting brushfires of freedom in the minds of men.” The Fayette County GOP might consider an update. Registered Republicans surpassed Democrats in Fayette this summer, making it the last county in the rapidly reddening region to flip to a GOP voter edge. The inversion reflects and continues yearslong changes to voter registration across the battleground state. And despite close inter…