The casualties are one reason behind a decline in support for both Bush and the war. A Gallup Poll conducted for CNN and USA Today in late September, for example, found that 59% of those surveyed called the war a "mistake" — the highest figure since the poll began asking that question at the war's onset.
The same poll showed Americans sharply divided on whether to withdraw or maintain the current troop level. Several polls have shown Bush's overall popularity at a low ebb.
In downtown San Diego on Tuesday, the father of a Marine killed in Iraq joined another protester in a lonely vigil at Horton Plaza aimed at gaining the attention of shoppers and office workers hurrying home.
Fernando Suarez carried a poster with a picture of his son, Lance Cpl. Jesus Suarez del Solar, who was killed south of Baghdad more than two years ago. "Two thousand is too many," he said. "One is too many. It's time that the community demand: No more money for war, no more lies."
Few people stopped to talk with Suarez. Suarez, speaking Spanish, tried to talk with three Latino teenagers wearing Junior ROTC uniforms, but they hurried away.
An Elvis impersonator, accompanied by a boy in a wolf mask, drew a larger audience 25 yards away from the vigil.
In Oakland, the Bay Area Veterans for Peace lighted 2,000 candles and set them afloat on Lake Merritt to commemorate the dead.
Among the organizers was California National Guard Staff Sgt. Diana Morrison, 37, of Alameda, who said she served in Iraq from June 2003 to January 2004 as a Humvee turret gunner with the 270th Military Police Company from Sacramento.
"I joined the National Guard to help out with state emergencies, but I went to Iraq hoping we could do something good," she said. "I quickly saw that we weren't helping anyone."
More protests are planned for today, including in Oceanside, home to Camp Pendleton. More than 300 Marines from the base have been killed in Iraq.
Many American soldiers and Marines in Iraq who have seen their buddies die said this week that morale remained high, bolstered by a need to give meaning to those deaths and to protect one another as the war's toll continues to rise.
"It's going to keep going up until it's over," said Spc. Francisco Gutierrez, 21, of Odessa, Texas, a paratrooper with the 2nd Battalion, 325th Airborne Infantry Regiment, on a mission in Tall Afar in northern Iraq.
Gutierrez said he had lost his Ft. Bragg training partner and needed to keep fighting so that his companion's death would not be in vain. "It's not about revenge," he said, "but finishing what we started."
"It gets rough here but most know what the purpose is," said Sgt. Frederick Shinlever of the same regiment, adding that several of the 2,000 dead were his friends.
"It makes you want to fight, and clean the place up even more," said the 35-year-old from Indianapolis. "If we were to pull out, it'd be a lost cause."
A growing number of American dead in Iraq have come from National Guard and Army Reserve units.
This trend made Army reservists from the 401st Civil Affairs Battalion, based in Webster, N.Y., feel particularly vulnerable Sunday as they rolled out of their base in Mosul in northern Iraq over a treacherous road to the city of Dahuk.
Under his T-shirt, Sgt. Dan Fink, 22, wore a cross, two saints on small medallions and a silver dollar his grandfather carried in the Korean War.
"Over here, I'll take all the help I can get," he said.
A few hours later, their mission complete, the reservists piled out of three Humvees.
"We made it," said 22-year-old Sgt. Trinity Uemura, smiling. "It's like we hit the jackpot. No one was hurt."
Boudreaux reported from Baghdad, Roug from Tall Afar and Richter from Washington. Times staff writers Borzou Daragahi in Baghdad, Tony Perry in San Diego and Rone Tempest in Oakland contributed to this report.