Obama to deliver eulogy for slain Charleston, South Carolina pastor Clementa Pinckney today

South Carolina will take a step forward in healing the wounds of last week's mass shooting when President Barack Obama arrives on Friday to deliver the eulogy for the pastor of the historic church where the attack took place.

Reverend Clementa Pinckney, a widely admired state senator and pastor of Charleston's Emanuel African Methodist Episcopal Church, was among the nine people who died when a gunman opened fire during Bible study.

The massacre has sparked an intense dialogue across the southern United States over the legacy of slavery and its symbols, centering on the Civil War-era battle flag of the Confederacy.

Addressing the shooting last week, Obama said it raised questions "about a dark part of our history."

Nicknamed "Mother Emanuel," the Gothic Revival-style house of worship is the oldest A.M.E. church in the southeastern United States, and was founded by slaves.

In an unusual step, Obama will be accompanied by both First Lady Michele Obama and Vice President Joe Biden for the funeral in a Charleston college arena. All three knew Pinckney personally.

During his presidency, Obama has spoken at half a dozen memorial services for victims of mass shootings in Texas, Arizona, Colorado and Connecticut.

"I’ve had to make statements like this too many times," a visibly upset Obama said from the White House last week. "Communities like this have had to endure tragedies like this too many times."

Obama repeated previous calls he has made for tougher gun laws, a politically thorny issue in the United States where the constitution guarantees the right to own guns.

"At some point, we as a country will have to reckon with the fact that this type of mass violence does not happen in other advanced countries. It doesn’t happen in other places with this kind of frequency," he said.

Married with two children, Pinckney was a talented orator with a baritone voice and began preaching at 13. A Democrat, at 23 he became the youngest African-American in South Carolina history to be elected to the state legislature.

Several thousand turned out on Thursday evening for Pinckney's wake at Emanuel, the line of mourners stretching for three blocks, including 200 college fraternity brothers, friends, politicians and members of the public, both black and white.

"I cried when I got here," said Katharine Moseley, a Texas bus driver who drove 20 hours from Austin. "I was raised in the A.M.E. church."

Lutheran bishop Mike Rhyne also drove down with his wife and three children from central Pennsylvania to pay tribute to his friend and fellow seminary student. "He was one of the best men I have ever met," he said.

Pinckney's high school friends Kevin Riley, 41, and Lachandra Colbert, 42, traveled from Maryland for the funeral. "We wouldn't miss this. He was our classmate," said Riley. "He was on track to be someone really important," Riley added.

Mourners universally echoed the words of forgiveness by relatives of their slain churchgoers for the white man, Dylann Roof, accused of the murders.

"We are not the ones to judge, we leave that to God," said Maxine Frasier Riley, 65, a retired school guidance counselor.

The Department of Justice has opened a hate crime investigation into the shooting.

Roof posed with the Confederate flag in photos posted online and allegedly made racist remarks to his victims as he opened fire.

In the aftermath of the slayings, South Carolina Governor Nikki Haley and other Republicans have called for the flag's removal from the State House grounds, saying it is divisive.

The controversy has spread across the country, with politicians adding to voices clamoring for the removal of Confederate symbols and names, and major retailers removing merchandise with Confederate images from stores and websites.