(Bloomberg News) Valerie Jarrett, a senior advisor to Barack Obama, said the president would work with the business community to overhaul the tax code in a second term as Democrats today kick off their national convention that aims to propel his re-election bid.

"Let's broaden the base, let's reduce the rate," Jarrett said at a Bloomberg breakfast in Charlotte, North Carolina, the convention site. "That means we are going to close some loopholes, but that's going to benefit the broader business community."

"The long-term sustainable growth rests with the private sector," she said. "The president knows that."

Obama campaigned in Norfolk, Virginia, today on the final stop of visits to battleground states ahead of his acceptance speech at the convention on Sept. 6. Headline speakers at tonight's opening session include keynoter Julian Castro, the mayor of San Antonio, Texas, and first lady Michelle Obama. Party officials start the convention at 5 p.m. local time.

"We've come too far to turn back now," Obama told a crowd of about 11,600. "On Thursday night, I will offer what I believe is a better path forward, a path that will create good jobs."

Obama Frustration

Jarrett today said that while the president is frustrated with Republican lawmakers who have consistently opposed his agenda, he'll continue to try work with them.

"He's never going to give up on that," she said.

Obama's nomination speech will be more specific than Republican Mitt Romney's in detailing a path forward on deficit reduction and will emphasize tax fairness over Medicare, top aides said.

The address will tell Americans "where we've been and where we need to take this country," campaign manager Jim Messina said at a separate Bloomberg breakfast in Charlotte today.

Deputy campaign manager Stephanie Cutter at the event said the speech will be "aspirational" and "pragmatic," and will "lay out a tangible path forward" with "a pretty clear sense of what the second term will be about."

Cutter and Messina declined to preview specifics of the president's convention address.

Romney in his address to the Republican convention last week in Tampa, Florida, sought to identify with the dreams and disappointments of U.S. voters amid high unemployment, saying Obama's 2008 campaign promise to bring "hope and change" has given way to "disappointment and division."

Defending Obama

Cutter defended Obama's record when asked whether the country is better off now than four years ago. She said even if Americans may not feel so individually, "The country is stronger" for Obama's success against al-Qaeda, for his domestic policies, including expansion of health-care coverage and insurance protections, and for ending the war in Iraq and winding down the fighting in Afghanistan.

In an interview with a Colorado television station that aired yesterday, Obama gave himself a grade of "incomplete" on the economy.

Romney's campaign seized on the comment: "If he can't even give himself a passing grade, why would the American people give him another four years," Andrea Saul, a Romney campaign spokeswoman said in a statement today.

Obama campaign spokeswoman Jen Psaki told reporters traveling with the president that the Romney campaign "clearly hasn't done their homework." The president has made similar remarks before to indicate he has more work to do, she said.

Protest March

In the streets of Charlotte, four rows of police today surrounded and blocked a group of more than 75 Occupy Wall Street protesters attempting to march from their encampment in a city park toward the Convention Center, where Democratic delegates held midday meetings and the news media are headquartered.

Some marchers carried a cloth banner that said "Free Pfc. Manning. Whistleblowing is not a crime." The sign referred to Bradley Manning, the U.S. Army private accused of leaking hundreds of thousands classified military and diplomatic documents to WikiLeaks.

'War Parties'

"Both the Democratic Party and the Republican Party are war parties" said a speaker whose voice was broadcast by a portable loudspeaker from inside the police cordon.

One protester was arrested for trying to cross police lines, Charlotte-Mecklenburg Police Chief Rodney Moore said.

The Democrats' three-day convention will feature ordinary Americans -- many of whom have introduced Obama at campaign events -- talking about how his policies on health care, the bailout of the auto industry and other issues have benefited them personally, Democratic officials told reporters at a briefing today.

Michelle Obama will talk about the president as a husband, father and friend, as well as the values that motivate his decisions, the officials said.

Obama told supporters in Virginia he'd be watching his wife's speech at home with the couple's two daughters.

"I am going to try not to let them see their daddy cry," he said. "Because when Michelle starts talking, I start getting all misty."

Castro, a Stanford University and Harvard Law School graduate who is the first Hispanic to deliver a convention keynote speech, will talk about his personal story and the future of the Democratic Party.

Hispanic Vote

Hispanics may account for 8.9 percent of the U.S. electorate in November, up from 7.4 percent in 2008, according to a report last month by the Center for Immigration Studies, a Washington-based research institute.

Support from Hispanics helped Obama win the White House four years ago, and this year their votes could be crucial in battleground states including Florida, Colorado and Nevada.

Also speaking tonight is Massachusetts Governor Deval Patrick, who will contrast Romney's vision of his achievements as that state's chief executive from 2003-2007 and what Democrats see as the negative impact of his economic policies.

Romney today is in Vermont preparing for October's three presidential debates and has no public events.

The convention's final night is scheduled to be moved from an indoor arena to the Charlotte's Bank of America outdoor sports stadium for Obama's speech. Convention planners say contingency plans call for holding the gathering in the smaller arena if severe thunderstorms move into the area.

Jarrett, when asked at her breakfast interview to list her regrets about the administration's first term, said Obama and his team should have "spent more time outside of Washington in that first year."

Jarrett said a better job of energizing Democrats nationally would have helped the party avoid its losses in the 2010 congressional elections, which included Republicans taking control of the House.

Obama "didn't appreciate early on how important it was to tell" his side of the story, she said.