Obama's campaign is pulling out of its third longshot state, North Dakota, AP reports from Bismark today, shutting 11 offices and moving staffers to Wisconsin and Minnesota, states John Kerry won in 2004.

This is the third state that appears to have come off the table since Obama's campaign laid out an ambitious 18-state battlefield. His campaign also pulled out of Georgia, and Sarah Palin's nomination appears to have put Alaska out of reach.

At a briefing for reporters in June, Obama campaign manager David Plouffe recognized that the battlefield wouldn't remain that wide to the end.

"We have a lot of differing combinations to get to 270, and our strategic imperative is going to be ... to keep as many of those scenarios as possible alive" deep into October, he said.

Over the next 40 days, other states will likely come out of play; the question is how long some of those, from huge ones like Florida to marginal Montana, remain on the table, as well as how competitive McCain can keep his own forays into the Kerry states, in Wisconsin, Michigan, and New Hampshire.

By Ben Smith, Politico, September 22, 2008