(CNN) -- With Mitt Romney's victories in the April 24 Republican primaries, a new phase of the campaign began at Obama re-election headquarters in Chicago. After a year spent hiring staff and building an organization, Obama for America finally had what it had been waiting for: an opponent.
"The monologue is over," Obama campaign manager Jim Messina said the day after Romney's conclusive five-state primary sweep. "Now Romney has to put his record and his agenda up against the president's, and we look forward to that debate. The general election might just be starting, but we've been at this for more than a year in Chicago."
This year of preparation certainly gave the Obama campaign a head start on building up a national organization, but it also allowed the campaign leadership to map out a message for the early weeks of the general election.
The map has included a campaign kickoff just days after the one-year anniversary of Osama bin Laden's death, a huge push by the president on the issue of student loans and an aggressive attempt to define Romney as out of touch with the struggles of middle-class Americans.
Even the president's recent announcement that he now supports same-sex marriage appears to have been scheduled as a part of the campaign's rollout. Senior advisers to the president say Obama was always planning to announce his new position before the Democratic convention in September, probably at a time when his Democratic base needed energizing.
But the timing of the announcement was moved up after Vice President Joe Biden told NBC's "Meet the Press" on Sunday that he supported same-sex marriage.
Since their candidate effectively secured the nomination, Team Romney has been forced to keep pace with an Obama message machine that's been up and running in some form or another since 2007, all while rapidly hiring staff and building its own nationwide organization to compete in November.
In the first week after Romney became the de facto Republican nominee, the president's re-election campaign bought airtime in swing states to run a negative television ad attacking Romney's image as a job creator. A week later, it released another ad, this time largely ignoring the opposition and focusing instead on the difficult economic situation Obama inherited in 2009 and the jobs created in the three years since.
The team in Chicago also posted more than half a dozen campaign videos on its website, each raising questions about Romney's positions or trying to undermine Romney attacks against Obama.
As for the president himself, by the time polls closed April 24, he had already embarked on a three-state college tour to rally support for legislation that would prevent interest rates on federal student loans from doubling. This public push forced Romney to come out in favor of congressional action to extend the lower rates -- a day ahead of Republican leaders on Capitol Hill.
To highlight the president's national security record, one of his strongest issues with independent voters, Obama for America released a video narrated by former President Bill Clinton extolling Obama's decision to order the 2011 raid that killed bin Laden and questioning whether Romney would have made the same move. A few days later, the president made a surprise trip to Afghanistan, addressing a crowd of servicemen and -women and delivering a speech to the nation from Bagram Air Base on the future of U.S. involvement in the region.
While many Republicans griped that these actions unfairly politicized the military, veteran political strategist Mark McKinnon said that by publicly complaining, they merely assured that more attention would be paid to an issue helpful to the president.
"I think Team Obama has come out of the gates aggressively in an effort to try and frame the race early on their terms," said McKinnon, a co-founder of the nonpartisan group No Labels and a former adviser to the presidential campaigns of George W. Bush and John McCain.
Senior Obama campaign adviser David Axelrod said his team had been mapping out the campaign for a year "and have been planning to take this next step and ramp up to this next step for some time, and so we're fulfilling our plan for this campaign."
The plan, as laid out by the campaign and executed by its candidate, seems to hinge on convincing voters that the president is fighting for middle-class Americans, whereas Romney would fight only for corporations and the wealthy.
At a recent campaign kickoff event in Ohio, Obama focused his economic message almost entirely on these populist themes. He decried corporate greed on Wall Street and Republican-supported tax breaks for the wealthiest Americans while expressing empathy for struggling middle-class families trying to keep up with rising costs while incomes shrink.
"We measure prosperity not just by our total GDP, not just by how many billionaires we produce, but how well the typical family is doing: whether they can go as far as their dreams and hard work will take them," Obama said.
This narrative helps the president frame Romney as his opposite: a defender of the upper class who, as the president said in Ohio, "sincerely believes that if CEOs and wealthy investors like him make money, the rest of us will automatically prosper as well."
"The challenge we faced for over a decade is that harder work hasn't led to higher incomes," Obama said. "It's that bigger profits haven't led to better jobs. Governor Romney doesn't seem to get that. He doesn't seem to understand that maximizing profits by whatever means necessary -- whether through layoffs or outsourcing or tax avoidance or union-busting -- might not always be good for the average American or for the American economy."
For its part, the Romney campaign has been laser-focused on jobs, a strategy that helped many Republican politicians claim victory in 2009 and 2010. Nearly every statement released by Romney's team in Boston includes a reference to the nation's unemployment rate, and during the primary, Romney regularly trumpeted his record of job creation in the private sector.
The strategy worked in that many polls show that most voters trust Romney more than Obama on issues of the economy, but it also played into the Obama campaign's efforts to paint Romney as pro-business rather than pro-middle class.
Now that the general election has begun in earnest, Romney seems to be making more of an effort to fight that perception.
"We are seeing a greater and greater gap between those that have the most and those that have the least," Romney said recently at an event in New Hampshire, touching on a favorite theme of the Obama campaign. "The president's focused on taking away from those that have the least. I want to help everybody particularly those that are being left behind. I want to help the poor. I want to help the middle class get the kinds of jobs that raise their income. Let's focus on helping the people who need the help the most."
Charlie Black, a veteran Republican strategist and informal adviser to the Romney campaign, said these efforts by Romney to tell stories that went largely untold during the primary will increase in the coming weeks. This will probably mean more biographical details will be unveiled to help introduce Romney to voters.
While Black sees the Obama campaign's rollout as "well-choreographed," he points to the tightness of recent national polls as evidence that Obama's "class warfare" strategy hasn't been entirely effective.
"It's been two weeks -- three weeks if you go back to when Santorum dropped out -- and Romney's already getting 90% of the GOP vote," Black said. "I would've guessed Obama would've been up 8 points by now, and by June, we could've caught up.
"Romney should still be nursing his wounds from the primary, but he's not."
Black, who's been involved in every Republican presidential campaign since 1976, sees some similarities between Obama's task this year and the uphill climb that George W. Bush faced in 2004. At the start of Bush's re-election campaign, he was personally popular, but the economy was slowing, and voters were growing tired of fighting an increasingly protracted war in Iraq.
"We used to have a fairly large pool of voters who liked Bush but didn't approve of his job performance. That's what Obama's got now," Black said, citing a recent Politico-GW Battleground Poll that found 24% of registered voters fit that description. "That pool of voters in Bush's case mostly went for Kerry. So the likeability part isn't as good an indicator as the job approval part."
The Battleground Poll supports Black's view of history. Of those voters who like Obama but don't approve of his performance as president, 68% say they will vote to replace him in November.
"Despite moving aggressively, however, they have to be concerned that the race looks like a jump ball when Romney is arguably at his most vulnerable," McKinnon said of the Obama re-election team. "The challenge for Obama is that his fate is almost entirely dependent on one variable: the economy."
While economic indicators are trending in the right direction for Team Obama, Black said that many voters make up their mind on their personal economic situation early in an election year, and that perception can be hard to change regardless of how the overall economy improves.