NEW YORK (AP) -- Rick Santorum doesn't care about the unemployment rate. Newt Gingrich has "more baggage than the airlines." Both are Washington insiders who have bent their principles for money and influence.
So say Republican presidential candidate Mitt Romney and his allies.
That advertising playbook has helped make Romney his party's likely presidential nominee and could offer a preview of what awaits President Barack Obama in this summer's general election campaign.
Voters in early primary states have seen plenty of this ad strategy already: a torrent of attacks on Romney's opponents along with a few positive spots about the GOP front-runner's biography and business experience. The strategy, devised by Romney's campaign and an allied independent group, has been focused and unforgiving, all but eviscerating the former Massachusetts governor's rivals while portraying the candidate as an effective manager and devoted family man.
"The ads have been very effective," says Jonathan Collegio, a spokesman for American Crossroads, a conservative-leaning super political action committee. They've catapulted Romney "into a very strong position in the Republican primary without going so far that he's alienated swaths of independent voters."
The general election phase of the campaign will tell whether that's true.
One thing that's certain is that the Romney team's approach has successfully shepherded him through a primary season in which voters have been far more conservative than the candidate was perceived to be.
Romney's team now faces a far greater challenge: persuading a more centrist general electorate to bounce Obama, who polling shows has much higher favorability ratings than his Romney himself.
The Romney campaign and Restore Our Future, a super PAC supporting his candidacy, together have poured about $50 million into television ads in the primary campaign so far, according to information provided to The Associated Press by ad buyers. No other candidate or super PAC has come close to that level of spending.
Restore Our Future, which is run by several former Romney advisers, has spent more than $35 million on TV ads alone, almost of which have been negative attacks against Santorum and Gingrich.
ROF's approach has been clear and unadorned: Cut straight to the heart of Romney's rivals' vulnerabilities, often using their own words against them. Make accusations about their records, citing news sources as support.
There are signs a similar approach will be used against Obama.
ROF has released one ad scoffing at the president's history as a community organizer and law professor. And while Romney's campaign itself has run mostly positive ads during the primary, it has released several online videos using Obama's words against him, including his observation in a TV interview that if the economy doesn't improve under his stewardship, his presidency will be a "one-term proposition."
Democratic media strategist Tad Devine says the approach has served Romney well so far but will face limitations against Obama, who, unlike Romney's Republican rivals, will not lack for resources to go after his challenger on the air
"There's a great risk to the strategy he's pursued," Devine said of Romney. "When you define yourself as totally negative, you don't give voters any reassurance against the attacks that might be made against you."
Devine, who advised Democrat John Kerry on media strategy during Kerry's unsuccessful effort to unseat President George W. Bush in 2004, said Kerry's campaign had run largely positive ads about the Massachusetts senator even after the Bush campaign went on the air with attack ads. A host of liberal-leaning independent groups ran negative ads against Bush, but they were less closely aligned with the Kerry campaign than the current breed of super PACs is to the GOP campaigns those groups support.
"The Romney campaign and Restore Our Future are not functionally separate," Devine said.
ROF clipped Gingrich's rise in Iowa and later in Florida by airing ads that slammed the former House speaker as an ethically challenged Washington influence peddler. The group also taunted Gingrich with his own words, noting the many times he said he'd made mistakes and boasted about working closely with President Ronald Reagan.
"Reagan rejected Newt's ideas," the ad said.
ROF has also slowed Santorum by painting the former Pennsylvania senator as an unprincipled deal-maker and an outspoken champion of home-state spending projects known as earmarks.
"I'm very proud of all the earmarks I put in bills," Santorum is shown saying in one ad.
In Wisconsin, which holds its primary April 3, Restore our Future is spending $2.3 million on ads against Santorum, including one that begins and ends with a clip of him saying "I don't care what the unemployment rate's going to be. It doesn't matter to me."
Santorum made that remark at a campaign appearance earlier this month in Illinois. He later clarified his comment by saying his campaign was about freedom from an intrusive government, not just monthly jobless figures.
Collegio, the spokesman for American Crossroads, one of many independent groups that are expected to spend millions this year attacking Obama, said Romney and Republicans wouldn't be alone in running negative ads during the campaign.
"Obama will have a much harder time winning if it's a referendum on him and his administration. More than anything they want 2012 to be about their challenger," Collegio said. "And if that's Mitt Romney, it means (his former private equity company) Bain Capital, his net worth and other things they view as comprising Romney's negatives."
Ken Goldstein, of Kantar Media/Campaign Media Analysis Group, which tracks political advertising, said the TV ad strategy on both sides may bear little resemblance to how the Republican nominating contest has gone so far.
"People either love or hate Obama, and those in the middle, who are going to decide the 2012 election, haven't tuned in yet," Goldstein said. "Do you think they'll be moved more by ads or by realities like the economy?"
Follow Beth Fouhy on Twitter: http://www.twitter.com/bfouhy