What happened to that Democratic turnout machine?

For years now, we've been told that there really are no more persuadable voters, and that strategists can pinpoint with creepy precision where their voters live and what TV shows they watch and what kind of soap they use, and any given election is all about getting those voters to the polls. Campaigns keep a secret list of turnout targets — essentially a percentage of the vote needed in every district to ensure victory — and most of the money spent by groups on both sides, which totaled something like $4 billion in this midterm cycle, is directed toward meeting them.

It'll be a while before we've all had a chance to go through the election data and draw any thorough conclusions, but what seems clear right now is that Republicans did a better job than Democrats of hitting their targets, just as they did in 2010. And this raises a pretty profound question about Barack Obama's ballyhooed turnout machine, which was supposed to be the baddest thing built by dudes with spreadsheets since the advent of the search engine.

Was it all just a mirage or what?

The answer here has implications far beyond what happened with the Senate this week, or even for 2016. It's really about the party's entire theory of success.

Remember that Obama's strategists didn't simply assume control of the Democratic Party when they won in 2008; they actually supplanted it. The idea was that his field operation, rechristened Organizing for America (as opposed to Obama for America) after the campaign, was far more sophisticated and space-age than anything Democrats already had in-house. So OFA moved into the Democratic National Committee and effectively took it over.

And what Obama's team had done in 2008 really was exceptional — like nothing Democrats had managed in a generation. By expanding the Democratic electorate and mobilizing a surge of younger and African-American voters, it had significantly expanded, too, the party's map of winnable states.

Democrats had queued up for hours in conservative-leaning states like Virginia, North Carolina and Indiana, delivering all of them into the Democratic column. In the process, Obama became the first Democrat since Lyndon Johnson — and only the third in 100 years — to break the 50 percent threshold. That was impressive.

In the afterglow of that victory, during the weeks in early 2009 when the OFA guys were plugging in their iPhones over at the party's new, sleek headquarters on Ivy Street, it was popular to suggest that a permanent realignment had taken place. I recall sitting on one of these postelection panels around that time, at Columbia's Graduate School of Journalism, and hearing some of my colleagues go on about this Rooseveltian, once-in-a-century shift that Obama had ushered in. Republicans were finished for 40 years, give or take a few; the new electorate was younger, more diverse and more liberal, and it was only going to get more so with each successive election.

Six years and three election cycles later, I think we can say: Yeah, maybe not.

Democrats will point to a lot of reasons that Obama's success in 2008 (and again, in a less dramatic way, in 2012) hasn't translated into lasting success for his party, and a lot of them are valid. For one thing, midterms are just different from presidential years and may register demographic changes more slowly. The midterm electorate always tends to skew older and whiter, and this year — with exit polls showing nearly one in four voters was over 60 — it skewed older and whiter than a "Matlock" rerun.

And Obama himself is stunningly unpopular, given where he was six years ago, and has always been something of a reluctant champion for his party anyway. Democrats in Congress haven't put forward any ideas that would mobilize their base the way the president did when he was running.

But the biggest reason for the disappearance of the new Democratic map is that the Obama surge never actually belonged to Democrats in the first place. It belonged to Obama — to his celebrity and his ironic detachment and his inspiring story. And like membership in any cool new thing, it was always going to be nontransferable, even had the president really tried to make it otherwise.

Politics in the modern era, especially among the younger and more diverse voters who have grown up without their parents' institutional loyalties, isn't about party. It's about ideology, yes, but largely about personality, too. It's about the visceral connection and symbolism that a candidate brings to the moment, not the platform committee or slogans or carefully scripted conventions with their silly placards and confetti from another time.

Thinking that the Democratic Party could simply absorb Obama's appeal among new voters was as misguided as thinking that a record label could somehow inherit Taylor Swift's fan base and use it to catapult every other artist on the list to stardom.

None of which means that Democrats can't win in 2016 or 2018 or any year after that; it's not as if Republicans have managed to broaden their appeal beyond the Bingo Night demographic for any longer than the current moment. The math is still moving inexorably in a more progressive direction.

But it does mean that every Democratic candidate, whether running for president or railroad commissioner, should expect to create his or her own math and election map, rather than relying on some master blueprint that was never very realistic for anyone not named Obama. Unless you happen to be the walking embodiment of social progress and political transformation, you probably shouldn't count on inspiring a legion of college students, or capturing 90 percent of an unusually high African-American vote, or opening up a 15-percent gender gap.

No turnout model on the planet, no matter how shrewd or high-tech, can make a party as compelling as a great messenger. Nor can it substitute the blather of an empty campaign for the power of an actual idea.