By BEN FELLER
AP White House Correspondent
WASHINGTON - For all the turmoil of the long primary season, President Barack Obama is right where he expected to be: taking on Mitt Romney and targeting him as a wishy-washy protector of the rich. With the November outcome likely to hinge on the economy, Obama will now engage more directly with the help of an experienced, well-financed campaign organization.
The campaign for the White House took on a decidedly different feel on Wednesday, a true two-man race for the first time. Yet even as Republican Rick Santorum's withdrawal a day earlier changed the dynamic, beginning the general election in earnest, the contours of the Romney-Obama race had already been becoming clear.
Both sides will keep pounding voters with ferocious arguments over who has the best vision for jobs, economic security and giving Americans a shot at a better life. In sharp and steady doses, directly or through aides, Obama and Romney will also accuse the other of being dishonest with voters and out-of-touch with their daily woes.
Everything gets faster and louder now.
Obama will pick his spots in targeting Romney directly until the election draws closer, needing to juggle the demands of his job and eager to remind everyone that he is the one who is already the president. Obama's Chicago-based campaign, meanwhile, will be working vigorously to challenge Romney and try to define him.
In a sign of the bitter fight ahead, Obama campaign manager Jim Messina went after Romney the day the race was joined: "The more the American people see of Mitt Romney, the less they like him and the less they trust him." The Obama campaign followed that on Wednesday with a video of some of Romney's most divisive or awkward moments during the Republican primaries, titled: "Mitt Romney: Memories to last a lifetime."
The events that shape the race may well be surprises to the candidates as well as everyone else, like the economic collapse of late 2008. If the campaigns have their way, however, the narratives are set: Romney assailing Obama as an economic failure who had his shot, and Obama depicting Romney as one who would gut middle-class America.
Essentially, Obama has already been running against Romney, who fell short in his 2008 effort to win the GOP nomination.
Every time Obama talks about millionaires paying a fairer share in taxes to help all of America, as he did again Wednesday, it is meant as a contrast to Romney and his vision. Vice President Joe Biden has been out giving a battery of campaign speeches that take on Romney, including another one on Thursday in New Hampshire.
And long before Santorum bowed out this week, Obama had been trying to define the election as a clear, basic choice. His pitch is that Romney will revert to a harmful trickle-down, let-people-flail philosophy instead of spending tax dollars on core priorities and using the government as an enforcer of fairness for all.
Romney sees Obama as a "throwback to the old-style Democrats of the past, big government, welfare state Democrats" who want America to become Europe.
The race is on. It's been on.
"I think people think about this as some kind of switch going off, but it really is more like a ramping up," Obama campaign strategist David Axelrod said as Romney's status as nominee was assured. "There's no big line of demarcation, because the arguments have been developing over a long period of time."
At the White House, spokesman Jay Carney said Obama will methodically get more into campaign mode. But he said the president is still in a period where he will talk more about the agenda in front of him, both in Congress and on the world stage, than about "his general election opponent."
Yet life gets blurry when a president runs for a second term. Political fundraisers in battleground states and near the White House have become staples of Obama's calendar. Even his official events, like a speech he gave on tax fairness at Florida Atlantic University on Tuesday, take on the unmistakable rah-rah feel of a campaign.
Romney, transitioning to his new role as all-but-sure nominee, showed a bit more swagger with Santorum out of the race.
"The president's campaign slogan was 'hope and change,"' he said to cheers and laughter in Hartford, Conn. "I think that's changing now to 'let's hope for change."'
The former Massachusetts governor stuck with his preferred message and itinerary, including Tuesday and Wednesday events in Delaware, Connecticut and Rhode Island, even though those heavily Democratic states will not be in play this fall. He also kept with his recent strategy of emphasizing his concern for women who own businesses, a clear sign that Democratic claims of GOP insensitivity to women have raised alarms.
Obama holds a double-digit polling advantage among women, who have made up a majority of the electorate in each presidential year since 1984. Overall, polling on the race has Obama on the upswing in a matchup with Romney, suggesting the president begins the contest with a slight advantage.
But his ratings on handling the economy remain in negative territory. A Washington Post-ABC News poll released this week said 47 percent say they trust Romney over Obama to handle the economy, compared with 43 percent who favor the president.
And trust - or the lack of it - is already defining the race.
Romney went off on the president's candor with the American people in a speech last week, saying an open-microphone moment with the Russian president about second-term "flexibility" reflected his brand of leadership. "He is intent on hiding. You and I will have to do the seeking," Romney said.
The Obama campaign has launched its own response effort. Said Axelrod: "One thing that we're going to be particularly vigilant about is monitoring what Gov. Romney says day-to-day, because sometimes it's harder to know whose record he distorts more - his own or the president's."
Obama's campaign has a sizeable cash advantage over Romney's, having more than $84 million in the bank at the end of February, Federal Election Commission records show. Romney's campaign had about $7.2 million.
This election cycle has also seen an explosion in the use of super political action committees, or super PACS, that can accept unlimited contributions, mostly from wealthy individuals but also from corporations and unions.
Romney especially benefited from such a super PAC, which unleashed a barrage of ads in key states to help crush his Republican competition. Obama flip-flopped on his opposition to super PACS, but one group set up to assist him has had trouble attracting seven-figure donations and lags behind its Republican-oriented counterparts.
Associated Press writers Charles Babington, Kasie Hunt, Ken Thomas and Jim Kuhnhenn and AP Deputy Director of Polling Jennifer Agiesta contributed to this report. Babington reported from Hartford, Conn.