Barack Obama, who has deployed more than 50 staffers in North Dakota in an attempt to become the first Democratic presidential candidate to carry the state since 1964, is pulling out.

An Obama spokeswoman, Amy Brundage, confirmed Sunday that the campaign's 11 North Dakota offices are being shut and its staffers dispatched to Minnesota and Wisconsin, where recent polls have shown a tight race between Obama and Republican John McCain.

She declined to say how many campaign workers were being shifted, but other Democratic activists put the number at more than 50.

McCain's campaign has no paid staff or offices in North Dakota. Last Thursday, the network of offices was used for a "Women for Obama Statewide Phone Bank Night" for supporters to call undecided women voters.

Obama has also run television advertising in North Dakota, which is unusual for a Democratic presidential candidate.

The campaign's decision comes just before North Dakotans will begin marking early ballots for the Nov. 4 election. Absentee voting may start as early as Thursday, and county auditors have reported getting thousands of ballot applications.

Democrats say the Obama campaign employees have been working to identify sympathetic voters, a task that is more difficult in North Dakota because the state does not have voter registration.

Minot attorney Jim Maxson, who was the first North Dakota "superdelegate" to the Democratic National Convention to back Obama, said he believes the Democrat still has a chance to beat McCain in North Dakota.

In any case, the Obama campaign's work for North Dakota Democratic candidates should give them a boost in November, Maxson said Sunday.

"In Minot, these folks have been working seven-day weeks, 12 hours a day, since July," Maxson said. "They're reaching a point of diminishing return on their efforts. I think this is a wise move for them to relocate, and we'll be fine."

A statement provided by Brundage said the Obama campaign "always knew it would be an uphill battle," but staffers "built a grassroots movement we are proud of, and an infrastructure that will help candidates up and down the ballot."

Attorney General Wayne Stenehjem, who is chairman of McCain's North Dakota campaign, said Sunday that Obama's withdrawal was not surprising. Recent public opinion surveys have shown McCain with a double-digit lead, and Obama's campaign probably had data confirming that, Stenehjem said.

"I'm sure they started to realize that there was no point to spend that money here, and they'd better put it to what they think might be a better use," Stenehjem said.

Gary Emineth, the chairman of the state Republican Party, said he believed McCain's selection of Alaska Gov. Sarah Palin as his running mate helped tip the balance decisively in McCain's favor in North Dakota.

"We had so much energy come to the McCain campaign when Sarah Palin hit the ticket," Emineth said. "It shocked me … I said, it's just a matter of time before (Obama) pulls out of the state and the race will be over."

Lyndon B. Johnson was the last Democrat to carry North Dakota when he swamped Republican Barry Goldwater in 1964. George W. Bush twice won the state easily.

"I'm not a trash talker, but I'll go out on a limb and say that it looks like Obama is going to be doing substantially better than the Democratic presidential candidates have done in the last two races, with or without these (Obama) folks here," Maxson said.