Former Gov. Jeanne Shaheen announced Friday that she will run again for the U.S. Senate seat that Republican John Sununu beat her out for in 2002.

In finally entering the race, Shaheen immediately becomes the favorite among the four Democrats seeking the job.

"We have major problems facing this country, and there is an urgent need for real change in Washington," Shaheen said in a statement to supporters.

"We've proven in New Hampshire that we can work together to get things done. I want to take that commonsense approach to Washington and help get this country moving in the right direction," she said.

Shaheen, 60, will step down as head of Harvard's Institute of Politics to campaign. She was the subject of a public draft effort and private recruitment by national party officials.

Activist Katrina Swett, Portsmouth Mayor Steve Marchand and former astronaut Jay Buckey fill out the field of Democrats, though Marchand has said he would drop out if Shaheen entered the race.

Shaheen lost by 5 percentage points in 2002, but the political landscape has changed dramatically since, mainly because of dwindling public support for the war in Iraq. National Democrats have made Sununu a top target for 2008 and have already run commercials criticizing his position on the war. His Manchester office routinely draws protesters.

Sununu wants to continue the effort in Iraq at least until Iraqi leaders get their political situation in order and has opposed any timetable for redeploying troops from Iraq. He is also a sponsor of a bipartisan bill supporting the Iraq Study Group's recommendations.

He was traveling Friday and not immediately available for comment.