The ominous precedent that exists is the 1960s, when the younger generation was going through a kind of cultural awakening and many were convinced that as soon as the WWI/WWII generations were dead that their generation would steward a more peaceful time. Then they all grew up and became conservative yuppies who now make up a huge portion of the Fox News viewership.
Unfortunately, there are a lot of young people out there who watched the Super Bowl who think that Madonna is pretty bad ass and that MIA was really rebelling when she flipped off the camera. These are the types that I count on to carry the conservative torch in 30 or so years. They may not be getting their message from the same news sources as the old conservatives of today, but as long as there's a bank account to protect somewhere, the world will have conservatives.
Ever really read up on FDR? She has a point. He was nearly overthrown in the Business Plot, in which Prescott Bush, Henry Ford and a few others tried to institute a Fascist government in the United States. "Republican" and "Democratic" didn't mean the same thing back then; I had a boss who pointed out that the Democratic party of today is a degree or two right of the Republican party of the '60s (Richard Nixon started the EPA and managed care, for chrissake). WWI was, from my understanding, the death throes of a Monarchist society in an Industrialist world. WWII, on the other hand, was an existential battle between Fascism and "everything else." The "liberal" and "conservative" values of our grandparents weren't gay marriage and single-payer healthcare. FDR shepherded Social Security; George Wallace tried to keep black kids out of white schools. The Equal Rights Amendment was 30 years from failing.
Economists like to call the period from 1947-1979 "The Great Prosperity." Sociologists, likewise, referred to those who grew up during that era as "The Me Generation" until that very generation turned around and tried to apply it to their kids. The entitlement of the Baby Boomers is well-known and well-researched; while the social change of the 60s was driven by idealism, its army burgeoned with ranks of those whose focus was a little more personal. "Get US out of Vietnam" ceases to be "liberal" when what you're really thinking is "Keep me out of Vietnam." Still, a little math:
If you were born in 1945, you were 23 when RFK and MLK were shot. You were 29 when Nixon resigned. You were 35 when the Iranian Embassy hostages came home. You were 42 for Iran Contra, 55 for the Lewinsky Scandal, 63 when the first black man was elected president...
... and today, you're still 9 years under the median age of Fox News viewers.
I think if you really look at the conservative movement today, you won't see idealists. You'll see opportunists. And for reasons outlined here:
http://www.reddit.com/r/AskReddit/comments/8d9zi/anyone_else...
And for the reasons outlined above, the "fiscal/social conservative" bait and switch isn't working any more. It is my measured opinion that throwing out hatebait in order to earn votes will cease to be an effective strategy in ten years or less.
Nixon wasn't all that bad by today's standards (god my dad, who is hippie artist born in '47 would kill me for saying so, but compared to NOW...). In addition to the things you point out, he also got us off the gold standard, something Europe did decades previous, and he also started the "War on Poverty". Both of these are antithetical to the Modern Republican ethos. FDR, as far as I've read, was the moderate Democrat of the time. The business elite hater him, but they assassinated Huey Long, who was poised to challenge him.
As for WWI and II, I can't recommend The Guns of August high enough, if you're at all interested in that history. Its a narrative history of the 1st month of WWI, and gives great perspective about the interrelatedness of the royal families of Europe, why war erupted, and the setup of WWII. turned me onto it. Its a history that is not told in enough detail in schools here, as it gets lost between the Civil War and WWII, but is absolutely fascinating. And, our world today is shaped by it, as it was the end of WWI that shaped the borders of many of the conflict areas of today (Mideast, Balkans, Africa).
http://dissentiscool.wordpress.com/2010/06/11/the-cuban-miss...
It's one of the best books, history or otherwise, that I've read.