And they're off.
President George W. Bush and Senator John F. Kerry of Massachusetts tangled Thursday over a variety of foreign-policy issues in their first debate, including the nuclear threat posed by North Korea and the widening genocide in Sudan. But it was Iraq that dominated the discussion from the get-go and produced the most heated disagreements.
Almost immediately, Senator Kerry questioned the president's decision to lead the U.S. to war in Iraq.
"This president has made, I regret to say, a colossal error of judgment — and judgment is what we look for in a president of the United States of America," Kerry said.
For his part, President Bush defended his decision to deploy U.S. troops to the region, arguing that Iraq is now an important front in the global war on terror.
"The best way to protect this homeland is to stay on the offense," he said. "We have to be right 100 percent of the time, and the enemy only has to be right once to hurt us."
The president appeared to apply the best-defense-is-good-offense strategy to the debate as well. He wasted little time in lambasting Kerry for contradictory statements and votes on Iraq. Kerry voted to authorize the use of force in the Senate, then voted against an $87 billion military-funding package for Iraq.
"The only thing consistent about my opponent's position is that he's been inconsistent," said Bush, later adding, "you cannot lead if you send mixed messages."
Despite the disagreements, the tone of the discussion between the two men never boiled over into anger. Abiding by the event's strict rules, the candidates did not interrupt.
The one light moment of the evening came after Bush complimented Kerry's daughters for reaching out to his daughters, Jenna and Barbara, recent graduates of the University of Texas and Yale.
A few minutes later, Kerry drew laughs from the audience saying of the Bush girls, "I've chuckled a few times at some of their comments."
Bush: "I'm trying to put a leash on them."
Kerry: "I've learned not to do that."
On the campaign trail, the senator has been known to give meandering, long-winded remarks. But Thursday, he spoke succinctly and declaratively, especially as he lit into Bush's record.
During the run-up to war, the president successfully linked Saddam Hussein to al Qaeda in the minds of many Americans. Polls at the start of the war indicated that a majority believed Saddam played a role in the attacks of September 11.
Kerry was effective as he sought to disconnect the two Thursday, arguing that Bush had been distracted by Saddam when Osama bin Laden was the more important target.
"Saddam Hussein didn't attack us. Osama bin Laden attacked us," said Kerry before criticizing the president for failing to capture bin Laden when he was surrounded in the mountainous Tora Bora region of Afghanistan.
By contrast, the commander-in-chief, regarded as the more naturally gifted campaigner, often appeared agitated or annoyed as Kerry launched his attacks. But Bush capably stayed on message throughout the evening, never straying from his central argument that only he has the strength and conviction to lead the nation in wartime.
Repeatedly, Bush said that Kerry's criticism of the operations in Iraq undermines the morale of U.S. forces there.
"Wrong war, wrong time, wrong place?" Bush said. "What message does that send our troops?"
The candidates did manage to find common ground on one issue during the debate, which was held on the campus of the University of Miami in Coral Gables, Florida. In response to prodding from moderator Jim Lehrer, host of PBS' "News Hour" program, they agreed that the greatest danger facing the United States is nuclear proliferation.
On Tuesday, the vice-presidential contenders will square off in Cleveland. Bush and Kerry will debate two more times as well, on October 8 and 13.
[This story was updated at 07:15 a.m. ET on 10.01.2004]