The tragic mass shooting at a black church in Charleston, S.C., has also rippled through the 2016 campaign, with the historic city in the key primary state a frequent stop for presidential candidates.
Jeb Bush, who was scheduled to visit Charleston on Thursday, announced overnight he would cancel the day's events in the wake of the shooting, which left nine dead.
"Governor Bush's thoughts and prayers are with the individuals and families affected by this tragedy," an official with the Republican's campaign said.
Donald Trump, who recently entered the race, also is postponing his scheduled Friday trip to the state, saying: "The tragic events that occurred on Wednesday evening should be our nation's primary focus for the foreseeable future. This is a time for healing, not politics."
Hillary Clinton had been in Charleston before the shooting, meeting with community leaders and holding a fundraiser. She is set to be in Nevada on Thursday.
After learning of the shooting, the Democratic presidential candidate tweeted: "Heartbreaking news from Charleston -- my thoughts and prayers are with you all."
One of the victims of Wednesday's shooting was state Sen. Clementa Pinckney, who reportedly had come to Charleston that day to attend the Clinton fundraiser before going to church. The suspected shooter was brought into custody by Thursday afternoon.
Other presidential candidates also expressed their sympathy.
Republican Sen. Lindsey Graham, who is from South Carolina, said: "We are all heartbroken by this tragedy.
"To the families of the victims, please know that you are being prayed for and loved by so many in the community and across the nation. I pray that God will provide you healing in the coming days," he said.
Graham was originally scheduled to campaign in New Hampshire this weekend, but his campaign office confirmed he is canceling those events and returning to South Carolina.
From other 2016 candidates:
Sen. Rand Paul, R-Ky., on Twitter: "Kelley and I are praying for everyone affected by this senseless tragedy in Charleston."
Sen. Bernie Sanders, I-Vt.: "The Charleston church killings are a tragic reminder of the ugly stain of racism that still taints our nation. This senseless violence fills me with outrage, disgust and a deep, deep sadness. The hateful killing of nine people praying inside a church is a horrific reminder that, while we have made significant progress in advancing civil rights in this country, we are far from eradicating racism. Our thoughts and prayers are with the families and their congregation."
Dr. Ben Carson, on Facebook: "Last night evil walked the streets of Charleston. My heart aches for the families of the victims. I pray for the families left behind. I pray for the community scared and hurting. I also pray you and I can conquer hatred. In my lifetime I have seen such great progress. Though racial based hate is still very much alive as last night so violently reminded us. But I worry about a new hate that is growing in our great nation. I fear our intolerance of one another is the new battle ground of evil. ... The America I know and love has fought evil all over the world to protect evil's victims. At home we must dedicate ourselves to not hating anyone based on their politics. Our leaders have walked our country down this path and it is up to us to change course."
Sen. Ted Cruz, R-Texas: "My thoughts and prayers are with the families of the victims of last night's shooting in Charleston, who were tragically taken from us as they gathered together in prayer inside their place of worship. While details are still emerging, I have faith in law enforcement that the perpetrator of this evil and senseless act will be brought to justice and prosecuted to the fullest extent of the law."
Former New York Gov. George Pataki: "There are no words to express our sadness and horror at the shooting in Charleston last night. While we are still learning the details of this senseless act, if early reports prove accurate, this hate crime is a particularly heinous form of violence. Hate crimes do more than threaten the safety and welfare of all citizens, they disrupt entire communities and cannot be tolerated by a civilized society. Our thoughts and prayers are with the victims, their families and the people of Charleston during this terrible time."
Sen. Marco Rubio, R-Fla., on Twitter: "Saddened by the news from Charleston. The victims and their families are in my prayers today."
South Carolina is the site of the first-in-the-South presidential primary, and is among the most-visited states early in the campaign, after Iowa and New Hampshire.