This is similar but not identical to a point I’ve often made: that the Republican Party is the party of people who are considered, by themselves and by others, as normal Americans—Northern white Protestants in the 19th century, married white Christians more recently—while the Democratic Party is the party of the out groups who are in some sense seen, by themselves and by others, as not normal—white Southerners and Catholic immigrants in the 19th century, blacks and white seculars more recently. Thus it’s natural for the Democrats to be more fissiparous.
The notion that Republicans are good, upstanding God-fearing Amurkins while Democrats are left-wing, communist, Jewish, homosexual pornographers plays an important role in America’s official political discourse. It’s there when candidates are criticized for not wearing socks and for vacationing in Hawaii. It’s there when other, more patriotic candidates invite reporters to barbecues at one of their many houses.
Also, feel free to make up your own jokes about public bathrooms, adult diapers, dildos, and wet-suits here.