… I get bothered sometimes when one thinks that one party will dominate for a generation or more (which is the aspiration of many D's around here too). Its pretty unprecedented and hasn't happened since post Lincoln.…
Your response wasn't directed at me. But I can say that a part of what you're touching on is what I find intriguing. I think not too many forum posters with their impressive knowledge historically concerning the Electoral College had that before they arrived here. (Oh, some did!) What I will admit is that I didn't notice five, ten, twenty years ago that the country has had many periods of living in realigning elections in which one party was dominant with winning the presidency.
I am a believer in Walter Dean Burnham's 30- to 40-year estimate of "cycles." That there is at least one catalyst which prompts a change that lasts for a long term. From when the Republican party first competed in 1856, those realigning elections began in 1860 (Republican; 7 of the next 9 cycles). The ones which followed were in 1896 (Republican; 7 of the next 9); 1932 (Democratic; 7 of the next 9); 1968 (Republican; 7 of the next 10); and I'll add to this 2008 (Democratic).
Realigning presidential periods were cited even before the Republicans of the 1850s. Though forum poster barfbag alluded to a pattern where one party tends to win no more than [2] consecutive cycles before a party-flipping of the White House, barfbag also has acknowledged, to some extent, cycles which went beyond two in a row. The last realignment saw a three-peat for the Republicans, with all from the 1980s, and no realigning presidential period—pitting Team Red-vs.-Team Blue—has had a limit of just two. Mathematically it cannot play out that way.