(CBS News) -- President Obama last year launched a line of attack against Republicans in Congress called "we can't wait." He used the line repeatedly to blast Republicans for blocking his ideas to revive the still sputtering U.S. economy, setting up a narrative reminiscent of President Harry Truman's famous 1948 campaign against the so-called "Do Nothing Congress."
It now appears he can't wait for the Republicans to finish up their nominating process either. While front-runner Mitt Romney is increasingly likely to become the party's nominee, he is still fighting former Pennsylvania Sen. Rick Santorum for the Republican nomination.
But the Obama campaign sees Romney as the eventual nominee and they are already attacking him as an aloof "rich guy" who does not understand the troubles of middle class Americans and would implement policies that would exacerbate the growing gap between rich and poor in the United States.
Vice President Joe Biden launched the line of attack in Ohio a few weeks ago, calling out Romney by name. And on Sunday's "Face the Nation," the vice president called the former Massachusetts governor
"I can't remember a presidential candidate in the recent past who seems not to understand ... what ordinary middle class people are thinking about and are concerned about," Biden told host Bob Schieffer.
But it was Mr. Obama himself who stepped up the attacks on Tuesday, launching a sharp broadside against both the House Republicans and the White House hopeful as he seeks to portray the election as a choice between two very different economic visions for America.
Laying out what is likely to be a recurring theme of his campaign, Mr. Obama said there is a stark contrast between his worldview and the Republican outlook for what the country needs.
"I believe this is a make-or-break moment for the middle class and I can't remember a time when the choice between competing visions of our future has been so unambiguously clear," Mr. Obama said in his remarks to the editors and reporters from the Associated Press at their annual gathering in Washington.
For his part,- using language strikingly similar to Biden, but directed at the president. In remarks after racking up three more primary victories on Tuesday night, Romney charged that it was Mr. Obama who was "a little out of touch."
"Under this president's watch, more Americans have lost their jobs than during any other period since the depression. Millions have lost their homes, a record number of Americans are now living in poverty," Romney said from Milwaukee, Wisconsin.
"It's enough to make you think that years of flying around on Air Force One, surrounded by an adoring staff of true believers telling you that you're great and you're doing a great job, it's enough to make you think that you might become a little out of touch," he added.
Meanwhile, Mr. Obama specifically called out Republican Rep. Paul Ryan's 2013 budget proposal on Tuesday, arguing that it would gut basic services for millions of Americans and labeling it "thinly veiled social Darwinism" and a "Trojan horse" disguised as a deficit reduction plan that would actually increase income inequality in the United States.
The president even mentioned Romney by name for the first time.
"One of my potential opponents, Gov Romney, has said that he hoped a similar version of this plan from last year would be introduced as a bill on day one of his presidency," Mr. Obama said as he detailed dozens of programs that would be cut under the Wisconsin lawmaker's proposal, deliberately tying Romney to the budget blueprint which passed the House but is unlikely to even be taken up for a vote in the Democratic-controlled Senate.
Norm Ornstein, a longtime political observer at the American Enterprise Institute, a conservative Washington think tank, said Romney's endorsement of the Ryan budget proposal makes it harder for the Republican candidate to attract independent voters he would need to court if indeed he becomes the nominee.
"A budget which offers substantial tax benefits for very rich people and draconian cuts that affect the middle class gives Obama an opportunity to paint Romney in a corner," Ornstein said, adding that the Obama campaign can also now say that Romney would "end Medicare as we know it" because his endorsement did not include an exception for Ryan's controversial Medicare proposal.
Ryan's plan for Medicare is less drastic than his 2011 proposal, but it would still make significant changes to the popular government-run program for seniors. This year's proposal would give seniors subsidies to purchase either private insurance or traditional, government-run insurance on an exchange, starting in 2023. Last year's budget plan became a lightning rod for criticism of the GOP, spurring Democrats to charge that Republicans wanted to essentially end Medicare.
Jennifer Duffy, a senior editor at the Cook Political Report, a non-partisan newsletter, said she does not "think it's an accident [Mr. Obama] is doing this now and he didn't do it in January," referring to the decline in the U.S. unemployment rate to a three-year low.
"As things improve, as the numbers get better, it is a much more salient argument to make and it becomes harder for Romney to turn around and hit him back," Duffy said. The Labor Department in March said the economy added more than 200,000 jobs for third straight month in February and the unemployment rate was at 8.3 percent, the lowest since the earliest days of the Obama presidency. The unemployment numbers for March will be released on Friday.
While presidents often try to remain above the fray and let others do the attacking for them, Larry Sabato of the University of Virginia's Center for Politics said Mr. Obama "does not have that luxury."
"They assume this will be a close competitive race and they should. The fundamentals call for a close competitive race and that means you have to engage," Sabato said.