WASHINGTON — The congressional debate over Iraq war funding is putting pressure on lawmakers of all political stripes, but none more so than Republicans who are facing tough re-election battles in 2008.

Democratic political operatives are targeting more than a dozen Republican House members who could be vulnerable on the war, along with at least three senators: Susan Collins of Maine, John Sununu of New Hampshire, and Norm Coleman of Minnesota. All of them hail from regions where the war is particularly unpopular and could be among the first to defect from the White House line as scrutiny mounts.

The focus on politically susceptible Republican lawmakers will surely increase as the party’s congressional leaders begin to wonder openly about how long their members will support President Bush’s troop surge in Iraq. The second-ranking Republican in the Senate, Trent Lott of Mississippi, warned yesterday that his party’s lawmakers would want to see definitive progress in Iraq in a matter of months.

“I do think this fall we’ve got to see significant changes on the ground in Baghdad and other areas … or else,” Mr. Lott said yesterday, according to Reuters. Those comments echoed remarks made by the House minority leader, Rep. John Boehner of Ohio, on Sunday.
“By the time we get to September or October, members are going to want to know how well this is working, and if it’s not, then what’s Plan B?” Mr. Boehner said on “Fox News Sunday.”

The Democratic leadership, eager for leverage to use with the White House in its war funding negotiations, quickly seized on the Republican doubts. “Now there are signs that the Republican leadership in Congress is beginning to think we need a timeline as well,” the Senate majority leader, Harry Reid of Nevada, said in a floor speech yesterday.

President Bush vetoed a Democratic bill that tied emergency funding to a timetable for withdrawal of American troops from Iraq. While Democrats are unlikely to insist on a similar requirement in a new funding bill, they may bring it up again when Congress considers a defense appropriations bill this summer. Senator Clinton and Senator Byrd of West Virginia are also urging a congressional deauthorization of the war.

The Republicans whose patience is thinnest are those who, like Ms. Collins, have already raised serious concerns about the direction of the war. Ms. Collins, who faces re-election in a blue state, last week joined Senators Warner and Nelson in writing a letter to the chairman of the Senate Armed Services Committee, Carl Levin, urging him to demand that the American commander in Iraq, General David Petraeus, brief lawmakers on the progress of the troop surge in early September.

Ms. Collins in January co-sponsored a resolution opposing the president’s decision to send additional troops to Iraq, but she also voted against the bill last month that would have mandated a timeline for pulling the soldiers out. She cautioned then that her vote was not an endorsement of an “open-ended commitment” of American troops. “If the president’s new strategy does not demonstrate significant results by August, then Congress should consider all options, including a redefinition of our mission and a gradual but significant withdrawal of our troops next year,” she said.

Many Republicans in the House are facing the same challenge. Rep. James Walsh, who represents Syracuse and won a close re-election campaign last year, seemed to crystallize the predicament in an open letter to constituents that he released yesterday. “Most Americans today want out of Iraq, as do I,” he wrote. “But the dilemma remains how we leave without making a bad situation worse.”

Like Ms. Collins, Mr. Walsh opposed the troop surge while voting against a binding exit timetable. Yet he acknowledged the importance of public opinion in his district — and his implicit vulnerability — by writing that “most of the people of Central New York tell me they want us to leave Iraq. I agree.” Ultimately, he said he would continue to vote against legislation that links funding with a withdrawal timetable, but only until September, when General Petraeus reports back to Congress.

While Democrats in Congress would surely love to see Mr. Walsh and other Republican congressmen join their side on the war, every vote they make in favor of continuing the conflict gives fodder to the Democratic Congressional Campaign Committee, which is looking to add to the party’s majority.

“Republicans have had an opportunity to be for benchmarks, and they’ve voted against them,” a committee spokesman, Doug Thornell, said yesterday. “They’re going to have a hard time explaining their votes to the American people.”

Democrats have sets their sights on the war record of a number of Republicans in districts that could tilt their way, including Rep. John “Randy” Kuhl Jr. of upstate New York, Rep. Thomas Reynolds of upstate New York, Rep. Christopher Shays of Connecticut, Reps. Mark Kirk and John Shimkus of Illinois, Rep. Ric Keller of Florida, and Rep. Thelma Drake of Virginia.