(CNN) -- The tenor of American political rhetoric became a centerpiece in the national debate over Saturday's attack by a gunman in Tucson, Arizona, that killed six people and left local Democratic congresswoman Gabrielle Giffords with a bullet wound to the brain.
Public leaders and others expressed sorrow about "a tragedy for the entire country," as President Obama put it -- a total of 18 people allegedly shot by 22-year-old Jared Lee Loughner.
But officials also voiced dismay Saturday over the possibility that highly polarized rhetoric in the conservative hotbed of Arizona may have played a role in the assassination attempt of the Democratic congresswoman, who was targeted during a meet-and-greet with constituents in a shopping center. A federal judge, a 9-year-old girl, and four other people died in the mass killing.
While not stating a motive for the shootings, Pima County Sheriff Clarence Dupnik in Tucson used a nationally televised press conference to condemn the tone of political discourse in his state. He charged that public debate is now "vitriolic rhetoric," which has rendered Arizona "the mecca for prejudice and bigotry."
Dupnik suggested that such rhetoric can have deadly consequences.
"We need to do some soul searching," Dupnik told reporters. "It's the vitriolic rhetoric that we hear day in and day out from people in the radio business and some people in the TV business.
"When you look at unbalanced people, how they respond to the vitriol that comes out of certain mouths about tearing down the government, the anger, the hatred, the bigotry that goes on in this county is getting to be outrageous. Unfortunately, Arizona, I think, has become sort of the capital," Dupnik continued.
"We have become the mecca for prejudice and bigotry," Dupnik said.
Arizona is a Republican stronghold where the party members hold a two-thirds majority in both chambers of the legislature and occupy the governor's office.
Dupnik is a Democrat.
"People who are unbalanced may be especially susceptible to vitriol," Dupnik said. "It's not unusual for all public officials to get threatened constantly, myself included. That's the sad thing that's going on in America. Pretty soon we're not going to be able to find reasonable people to subject themselves to serving the public."
Dupnik returned to the theme later in the press conference.
"People tend to pooh-pooh this business about the vitriol that inflames American public opinion by the people who make a living off of that. That may be free speech, but it's not without consequences," Dupnik said.
Last March, Giffords raised concerns about inflammatory rhetoric after her office was vandalized, and she cited how her name appeared on a website titled "Take Back the 20" as part of a list originally issued by Sarah Palin against vulnerable House Democrats.
A map on the site showed crosshairs over the contested Democratic districts.
Palin first posted the list in March 2010, naming 20 House members who voted for health care reform and represented districts that Republican Sen. John McCain of Arizona won in the 2008 presidential election.
At the time, Giffords responded to the map by saying on MSNBC that her long-serving colleagues had "never seen anything like it."
"The thing is, the way that she has it depicted has the crosshairs of a gun sight over our district," Giffords said in March. "When people do that, they've got to realize there's consequences to that action."
On Saturday, Palin posted a message on her Facebook page: "My sincere condolences are offered to the family of Rep. Gabrielle Giffords and the other victims of today's tragic shootings in Arizona. On behalf of Todd and my family, we all pray for the victims and their families, and for peace and justice."
Tom Fuentes, a former FBI assistant director who's a CNN contributor, described Dupnik's remarks as "a very emotional response by a very frustrated, hurt sheriff."
When media cover "hateful" public statements by officials or television personalities, those remarks are often framed as "they're exciting their base," Fuentes said.
"Law enforcement executives out there know, like this sheriff, that it also excites the lunatic fringe," Fuentes said. "In this country, we have no shortage of mentally unbalanced people, and it seems in case after case, they have no trouble obtaining firearms. So when they go over the edge and go public and try to initiate an attack, this is what happens."
Arizona state Rep. Matt Heinz, a Democrat and a Tucson physician, supported Dupnik's remarks.
"I think he is very, very correctly calling attention to some of the vitriol and some of the ways we're talking about each other," Heinz said. "For those with troubled minds, sometimes some of those things that are said are unfortunately taken in the wrong way."
Arizona state Rep. Steve Farley, a Democrat from Tucson, said that the country now faces a challenge of overcoming polarizing politics. His political aide witnessed the shootings and applied pressure to Giffords' wounds, he said.
"The question is can we come together as a state and can we come together as a country and sort of put this harsh hyper-rhetoric that has caused people who are a little unhinged in the first place to go over the edge," Farley said.
"This country is something that deserves no less than a politics that rises above violence," Farley said.
McCain, the state's Republican senator, said he was "horrified by the violent attack on Representative Gabrielle Giffords and many other innocent people by a wicked person who has no sense of justice or compassion. ... Whoever did this, whatever their reason, they are a disgrace to Arizona, this country and the human race, and they deserve and will receive the contempt of all decent people and the strongest punishment of the law."
House Speaker John Boehner, R-Ohio, was among the many other lawmakers on both sides of the aisle who quickly condemned the shooting. "An attack on one who serves is an attack on all who serve. Acts and threats of violence against public officials have no place in our society," he said.
Former U.S. Rep. John Boccieri, a Democrat from Ohio, faced a threat last year when a man said he would burn down Boccieri's house. The man is facing jail time.
That threat came amid "the heat of the debate over the health care issue," Boccieri said Sunday. "Intimidation and threats of violence have no realm in our public discourse. We should make sure that we hold folks accountable like that and prosecute them to the fullest extent of the law."
In the wake of the shooting in Arizona, Boccieri said, "I would hope that our country would appeal to its better senses so we could tone down the heated rhetoric and discuss with a degree of civility these important concepts and issues."
He added, "Both sides in my opinion are guilty of this and we know that folks are struggling; they're at last end's rope in some instance, and some of this rhetoric could push folks over the top."
But Boccieri also warned against deciding too soon what may have fueled the Arizona shooter, since the facts of the case are still being investigated.
Public officials spoke of the tragic nature of the shootings, in which authorities said they are also seeking a second man as "a person of interest."
But officials inevitably broached the rancor of national politics.
In fact, the U.S. House of Representatives agreed Saturday that it will cease any discussion next week about repealing President Obama's health care reforms -- a law opposed by many Arizona Republicans and voters in a November ballot measure -- and instead address Saturday's shootings.
Tea Party Express Chairman Amy Kremer said she was saddened by the mass shooting.
"These heinous crimes have no place in America, and they are especially grievous when committed against our elected officials," Kremer said. "Spirited debate is desirable in our country, but it only should be the clash of ideas. An attack on anyone for political purposes, if that was a factor in this shooting, is an attack on the democratic process. We join with everyone in vociferously condemning it."
U.S. Rep. Emanuel Cleaver, D-Missouri, chairman of the Congressional Black Caucus, said he was "shocked and devastated by the tragic events of this day."
"Even though we do not have all the answers yet, we are all too familiar with the violent and polarizing climate in which we live," Cleaver said. "There is no place in American society for such senseless and terrible acts of extreme violence. Those of us in leadership must be overly cautious of fanning the flames of extremism in hopes to prevent another horrendous tragedy such as this."
U.S. House Minority Whip Steny Hoyer, D-Maryland, called the attacks "cowardly."
"Our form of government, like all human things, is imperfect and flawed, but one of its greatest virtues is its power to resolve questions of the greatest import without violence," Hoyer said.
Rev. Al Sharpton, president of the National Action Network and a former Democratic presidential candidate, also expressed alarm about the direction of political rhetoric.
"In church services ... clergymen ought to address the senseless violence that has too often raised its head of late in the social and political discourse of this country," Sharpton said.
Jeff Rogers, the Pima County Democratic Party chairman, made a plea for "civilized discourse."
"There's just a tremendous amount of anger right now, a lot of people fomenting that anger," Rogers said.
"We maybe need to re-examine a lot of things. For instance, one of the first things on the table at the state legislature this year is putting guns in schools. How crazy is that, given what we've seen here today? And I think we just need to have a more civilized discourse in our politics in this country. This state as well," Rogers said.
U.S. Rep. Jerrold Nadler, D-New York, said he hoped that inflammatory speech will subside in the wake of Saturday's shootings.
"We have no idea what his motivation was, but we do know that Congresswoman Gabrielle's campaign headquarters was shot at during the campaign last year. We do know that death threats were made against her," Nadler said.
"Whenever you have violent political rhetoric, there could be some nut who will take up and reach a conclusion that the speakers didn't want," Nadler added.
CNN's John Helton and K.C. Wildmoon contributed to this story.