The Whigs self-destructed over social conservatism (slavery) and that is very similar to what the GOP is doing now.
Now you're only expressing half the story. We need a Paul Harvey to finish the rest.
What then emerged? (The Republican party.)
And what was at the foundational core of that fledgling party's social agenda? (why in 1856 they said they would take on the "twin relics of barbarism.")
And what were those "twin relics?" (slavery & polygamy)
And did they indeed take them on? (Yes)
And how many years did that take them? [Lincoln signed the emancipation proclamation within a decade...even though the remnant of slavery lived on culturally; the feds finally got the Mormon church to cave in on polygamy 34 years later, even though mainstream lds polygamist unions continued into the early 1960s and additional (new) LDS plural unions continued at an approximate rate of 11-12 a year through 1910.]
And did the Republicans stop opposing polygamy en masse even when the LDS church formally caved in 1890? (No. When the Utah LDS voted in a polygamist Democratic would-be Congressman named B.H. Roberts in 1898, they sent two-dozen banners with 7 million signatures to congress, saying they didn't want Congress to seat Roberts, who took a third wife around 1894...AFTER the LDS manifesto. Congress then sent Roberts home).
And did Republican social leaders stop opposing the cultural remnant of slavery & racism? (No. Few people seem to realize that Martin Luther King was a Republican! And few people seem to realize that many early Mormons, upon Utah becoming a state, were Democrats precisely because of Republican opposition to polygamy)
So Wagglebee, what you call "self-destruction" was actually the door-opener for a new party to emerge and tackle the culture's greatest social issues of its day!
Ridiculous, morality is what keeps the original Protestant America voting conservative and it is the key to winning Catholics and minorities. If people only cared about money then there would be more than 226,000 registered libertarians and prop 8 would not have passed in California.