VIRGINIA BEACH, Va. — Mitt Romney's campaign has concluded that the 2012 election will not be decided by elusive, much-targeted undecided voters — but by the motivated partisans of the Republican base.

This shifting campaign calculus has produced a split in Romney's message. His talk show interviews and big ad buys continue to offer a straightforward economic focus aimed at traditional undecided voters. But out stumping day to day is a candidate who wants to talk about patriotism and God, and who is increasingly looking to connect with the right's intense, personal dislike for President Barack Obama.

Three Romney advisers told BuzzFeed the campaign's top priority now is to rally conservative Republicans, in hopes that they'll show up on Election Day, and drag their less politically-engaged friends with them. The earliest, ambiguous signal of this turn toward the party's right was the selection of Rep. Paul Ryan as Romney's running mate, a top Romney aide said.

"This is going to be a base election, and we need them to come out to vote," the aide said, explaining the pick.

Another adviser, who also discussed strategy on the condition of anonymity, described the campaign's key targets as Republican activists: "The people who are going to talk to their neighbors, drive them to the polls on Election Day, and hold their hands on the way in to vote."

Asked last week about Romney bringing culture-war rhetoric into his stump speeches, adviser Kevin Madden dismissed the notion that it represented a strategic shift, and said while the economy is still the primary focus, the candidate will continue to talk about other issues he finds "important."

This attention to the base is a flashback to the politics of the last decade, in which George W. Bush won a narrow re-election with the help of conservative voters. But some Democrats have recently begun to speak in similar terms: Democratic Governors Association Chairman Martin O'Malley told BuzzFeed last week that Democrats had abandoned the search for "the magic argument for the three percent that are undecided" and begun to "just tell the base why you're doing what you're doing and why you're better than the other guy."

The campaigns' — and particularly Romney's — new focus on the base is driven by data. Recent public polls in major battleground states suggest the portion of the electorate that is truly undecided in this race is tiny, and shrinking. The latest NBC/Wall Street Journal/Marist poll showed that, with seven weeks to go until election day, just 6 percent of Ohio voters are undecided; in Florida and Virginia, the figure is 5 percent. And, of course, there's no guarantee those people will turn out to vote at all.

If Romney is going to win any of those states — all of which he's currently losing by several points, according to that poll — he'll have to change the makeup of the voters who turn out. Republicans have been griping for weeks that polls showing Romney behind tend to be built around samples based on 2008 exit polls, when excited Democrats flocked to the polls and many Republicans stayed home. Romney's goal is to ensure that the election day make-up of the electorate is different this time around.

As a result, several days on the campaign trail with Romney last week revealed a candidate almost jarringly different from the one projected from the stage in Tampa last month, and seen most often on TV.

Nationally, the Romney is running the campaign his Boston team has claimed to be running all along: a conservative businessman, wielding a laser-like focus on unemployment, and a promise to bring the American economy roaring back with a five-step plan. It's a message the punditocracy approves of, and the Republican establishment is comfortable with. It's also the message that helped Romney win the fundraising war over the summer, with wealthy business leaders eager to write checks for one of their own.

But last week, Romney's stump speech — once an unchanging recitation of the campaign's economic talking points that clocked in reliably at 18 to 20 minutes every time — was in a constant state of flux, with the candidate tailoring his remarks to elicit as many applause lines as possible from the partisans in the room.

In heavily-Evangelical Sioux County, Iowa, Romney's introductory speakers — including conservative Rep. Steve King — sermonized at length about keeping Christian values, and vouched for his love of Jesus Christ. In Virginia Beach, he spoke to a flag-waving crowd of veterans and military families — appearing alongside televangelist Pat Robertson — and built his remarks around patriotism, defense spending, and keeping God on the national currency.

In his prime time speech introducing Romney on the last night of the Republican convention, Florida Sen. Marco Rubio said his party didn't think Obama was a bad guy, just "a bad president" — a sentiment echoed in the nominee's relatively tame remarks.

But Romney has since dropped that line from his stump speech, and on the ground, he typically uses much harsher terms to describe the president.

Rick Wilson, a Republican strategist and ad-man, said the case against Obama's record will be made on the airwaves by the campaign and outside Republican groups — and it no longer needs Romney as a daily spokesman.

"On the outside, here's what going to happen: we're going to nuke Barack Obama into radioactive sludge in the swing states with 3000-4000 points of TV in September," Wilson said. "Crossroads and Restore [two Republican SuperPACs] will do the same. It's going to be hitting in concert with the terrible economic news, and it'll strike a chord."

That leaves Romney to spend most of his time on the trail delivering narrowly-focused messages meant to excite conservatives who weren't always behind him in the Republican primaries. (Ironically, what eventually won many of them over was Romney's argument that he would be the best candidate to win over moderate voters who traditionally decide the election.)

It has transformed Romney's road show from an almost robotic speech into a sometimes-passionate, and often unpredicatble, partisan appeal. Like an unassuming deli with an underground blackjack room in back, the Romney campaign's message looks presentable, if a bit dull, to the casual observer — but spend some time inside, and you'll find the edge.