CONCORD, N.H. (AP) – When he entered the U.S. Senate race this year, Portsmouth Mayor Steve Marchand said he’d drop out if former Gov. Jeanne Shaheen got in. She got in Friday; he dropped out Saturday, and announced he was supporting her.

“There is no doubt in my mind that we can compete one-on-one with John Sununu, however, this seat is too important to the state and the nation than to do anything less than to put up New Hampshire’s strongest candidate for 2008,” he said.

“Jeanne Shaheen, in my estimation, is the strongest candidate to defeat John Sununu in 2008,” he said.

If Shaheen wins the Democratic primary, the 2008 race will be a rematch with Sununu, who defeated her for the seat in 2002.

Sununu said Friday that he expects to run a town-to-town campaign, regardless of whom the Democrats pick.

In a telephone interview following his announcement, Marchand said the Senate race has statewide and national implications, as Democrats work to expand the gains they made last year.

“Frankly, this is about something much bigger than just me,” he said, acknowledging it was tough to drop out after putting months of time and effort into his campaign.

Marchand said he’ll probably run for another public office down the road.

“I would expect that sometime in the future, there’ll probably be other opportunities to work to represent New Hampshire and I look forward to those opportunities.”

Shaheen scheduled a news conference at her Madbury home for Sunday to give details on her decision.

As of Saturday, two other Democrats still were in the race for the party’s nomination to face Sununu.

Former astronaut Jay Buckey said he’s in the race to stay. He released a statement Saturday saying it was a pleasure to get to know and work with Marchand.

“I will miss deliberating the issues with him on the campaign trail over the year to come,” he said.

Activist Katrina Swett has been noncommittal. She released a statement Friday saying she was still committed to ensuring Sununu is defeated. Her campaign did not elaborate when asked if that meant she was staying in or dropping out.

Marchand said he has spoken to Shaheen about her decision, but declined to comment on what the conversation was about. He deferred remarks about his future with the Shaheen campaign until after Shaheen’s event on Sunday.