"The Emerging Democratic Majority" is the title of a 2002 book co-authored by John Judis. The book essentially argued that demographic changes were creating a "new progressive era" akin to the conservative era that marked the Reagan years. While President Ronald Reagan had "Reagan Democrats," early-2000s Democrats had increasing built-in advantages, too.

"Women are still voting more Democratic than men, but they are also voting much more Democratic than Republican, particularly women who now work outside the home, single women and women with college degrees," the book said. "Minorities, once about ten percent of the voting electorate, now constitute nineteen percent. ... They, too, are continuing to vote Democratic. Democrats are winning even more decisively in college towns, and these towns and their schools have become linked to entire regions like Silicon Valley and North Carolina's Research Triangle. And, skilled professionals have become a much larger and a dependably Democratic voting group."

For those unaware, the 2014 election wasn't exactly a good one for Democrats or progressives. In fact, the left-leaning party finds itself in worse shape in Congress and the states since the Great Depression -- i.e. before the last, real "progressive era" in American politics.

Reenter Judis, who offers something of a mea culpa in the National Journal, in a piece titled "The emerging Republican advantage."

These advantages remain partially in place for Democrats today, but they are being severely undermined by two trends that have emerged in the past few elections — one surprising, the other less so. The less surprising trend is that Democrats have continued to hemorrhage support among white working-class voters — a group that generally works in blue-collar and lower-income service jobs and that is roughly identifiable in exit polls as those whites who have not graduated from a four-year college. These voters, and particularly those well above the poverty line, began to shift toward the GOP decades ago, but in recent years that shift has become progressively more pronounced.
The more surprising trend is that Republicans are gaining dramatically among a group that had tilted toward Democrats in 2006 and 2008: Call them middle-class Americans. These are voters who generally work in what economist Stephen Rose has called "the office economy." In exit polling, they can roughly be identified as those who have college — but not postgraduate — degrees and those whose household incomes are between $50,000 and $100,000. (Obviously, the overlap here is imperfect, but there is a broad congruence between these polling categories.)
The defection of these voters — who, unlike the white working class, are a growing part of the electorate — is genuinely bad news for Democrats, and very good news indeed for Republicans. The question, of course, is whether it is going to continue. It's tough to say for sure, but I think there is a case to be made that it will.

This piece, notably, comes just two years after Judis's co-author on that 2002 book, Ruy Teixeira, declared their thesis to be even truer than it had been a decade before. In the 2012 Atlantic piece linked above, Teixeira says of President Obama's reelection victory:

We are now ten years farther down this road and (George) McGovern's revenge only seems sweeter.
...
It would be hard to imagine a better tenth anniversary present for The Emerging Democratic Majority! But will this new coalition be able to hold together over the long term? That depends on whether the Democrats can provide this coalition with what it wants and needs.

If you have whiplash, you're not the only one. If there's one thing today's electorate has been consistent at, it's being indecisive about which party it wants in charge.

This is not to pick on Judis and Teixeira. Political observers and journalists (The Fix very much included) are prone to over-analyzing the effects of a couple of elections or data points on the future of American politics. We all want to know what comes next, after all. And Judis and Teixeira, for what it's worth, didn't guarantee permanent Democratic majorities. (It's possible their thesis still carries weight. It's only been 12 years, after all.)

They are also hardly the first to venture into this territory. Karl Rove in 2000 foresaw a new Republican realignment that would be ushered in by George W. Bush. Two years later, Judis and Teixeira had the opposite thesis. Democrats won back Congress in 2006 and the presidency in 2008, while the GOP took the House in 2010 and then the Senate in 2014. And who knows what will happen in 2016?

And even after all that turnover, people are still predicting years of of domination by one party or another. Some Democrats like to think Republicans can't win a presidential race for a lot of the same reasons Judis and Teixeira laid out -- most notably the fast-growing Hispanic population. Republicans like to think their House majority is impenetrable for Democrats until 2022 at the earliest -- and maybe longer -- because Democratic voters are increasingly clustered into fewer and fewer districts.

The problem with this kind of crystal-ball analysis is that it often focuses on key bits of data while assuming most other data points will be more or less constant. Democrats were supposed to be the emerging-majority party because they did well among minorities. Meanwhile, we've seen Republicans compensate by doing better and better among working-class whites.

Politics has a way of balancing itself out -- not always, of course, but more often than not. And we are increasingly a 50-50 society; no presidential candidate has taken more than 53 percent of the vote since Reagan.

That doesn't mean Republicans don't have real problems going forward in presidential elections if they can't solve their Hispanic problem. Not does it mean Democrats have a good shot to win back the House sometime soon. But saying either of these things are written in stone is to forget lots and lots of political history.

And more often than not, we are not in anything amounting to a semi-permanent realignment. Indeed, it's hard to argue that the Reagan years even qualified as that.