Sens. Barack Obama and Hillary Rodham Clinton separately declared their support Tuesday for a March 31, 2008, cutoff in money for the Iraq war, Democratic presidential front-runners abruptly shifting positions on the issue at the heart of the 2008 race. The twin announcements came on the eve of a largely symbolic Senate vote, and as Connecticut Sen. Chris Dodd, another Democratic candidate, said in a campaign commercial that it was unfortunate his White House rivals "will not join me" in supporting legislation to set the cutoff date. Obama said he would vote to stop war funding as well as a second bill to set standards for the Iraqi government "not because I believe either is the best answer, but because I want to send a strong statement to the Iraqi government, the president and my Republican colleagues that it's long past time to change course." A few hours later, a spokesman for Clinton said she, too, would support the measure.