During an appearance in Portsmouth on the first day following the Democratic National Convention in Charlotte, N.C., the president gave credit to former President Bill Clinton for using his convention speech to clarify issues "in the way only he can."
"Somebody e-mailed me after his speech -- they said, 'You need to appoint him secretary of explaining stuff,'" Obama said to laughter and applause. "That was pretty good. I like that -- the secretary of explaining stuff -- 'splainin."
The president said he and Republican nominee Mitt Romney "have made their argument. There's a big choice to make."
"And I honestly believe this is the biggest choice, the clearest choice, of any time in our generation, because it's not just a choice between two candidates or two political parties," he said. "It is a choice between two different paths for America -- two fundamentally different visions for how we move forward."
Obama told the rally the Republicans "want your vote, but they don't want to show you their plan."
"And that's because they know their plan won't sell," he said. "That's because all they've got to offer is the same prescriptions that they've had for the last 30 years -- tax cuts, tax cuts, gut some regulations, oh, and more tax cuts."
During his acceptance speech Thursday, Obama said fixing the country's problems will take time but will be worth the effort.
"I won't pretend the path I'm offering is quick or easy -- I never have," Obama said during his televised address before 20,000 Democratic Party leaders and activists in Charlotte Thursday night.
"You didn't elect me to tell you what you wanted to hear. You elected me to tell you the truth. And the truth is, it will take more than a few years for us to solve challenges that have built up over decades.
"But know this, America: Our problems can be solved. Our challenges can be met. The path we offer may be harder, but it leads to a better place. And I'm asking you to choose that future.
"I'm asking you to rally around a set of goals for your country," Obama said, citing ambitions to create manufacturing jobs, slow the growth of college tuition and bolster trade.
He called them "a real, achievable plan that will lead to new jobs, more opportunity, and rebuild this economy on a stronger foundation. That's what we can do in the next four years."
As part of the plan, he called for the creation of 1 million manufacturing jobs by 2016, an achievement The Wall Street Journal said could be realized if a current manufacturing-growth trend continues.
The number of manufacturing jobs, 12 million in July, has returned to the levels of spring 2009. Manufacturing employment last stood at 13 million in November 2008.
The Romney campaign released a response to Obama's speech before it was delivered, assailing the president as having failed to create enough jobs, cut the deficit in half or increase incomes.
"This is a time not for him to start restating new promises, but to report on the promises he made," Romney said in the taped statement.
Obama, first lady Michelle Obama, Vice President Joe Biden and wife Jill Biden traveled to Portsmouth -- the first stop in a three-day campaign trip to battleground states, culminating in a bus tour of Florida's mid-state Interstate 4 corridor, perceived by both parties as having higher numbers of undecided voters than other parts of the state.
From Portsmouth, the president and vice president were to fly to Cedar Rapids, Iowa, where they were to speak at the University of Iowa. Obama was then to fly alone to St. Petersburg, Fla., Friday night before starting a bus tour Saturday morning.
The president is to campaign first in Seminole, Fla., near Tampa, his campaign said. Seminole is in Pinellas County, which flipped to Democratic from Republican in the 2008 election.
He is then to stop in Kissimmee, near Orlando, in Osceola County -- Florida's only minority-majority county and one that was key to Obama's victory in the state four years ago.
His bus tour will end Sunday with events in Melbourne and West Palm Beach.