"We are going to have the capability to talk to voters in their precincts and make sure they show up on that Saturday," when the caucuses are held in January, Plouffe said. "A caucus is a very, very different type of contest than a primary. Organization can be the key to success in a caucus."

Plouffe made the case that polls showing the Illinois senator trailing badly in Nevada are "very unreliable" for two reasons: Voters aren't paying much attention at this point, and a caucus, which requires in-person participation, isn't accurately predicted by polling.

"We do feel, in terms of phone calls and door knocking, that we've got the most active and aggressive campaign (in Nevada), and that's going to really pay off on caucus day," he said.

Plouffe also said that while the campaign hopes to get big Nevada labor endorsements from the Service Employees International Union and the Culinary union, "we can win Nevada without those."

"Obviously, both of those are very important unions," he said. "If you have them in your camp, they're terrific organizers in their own right, and they also have a lot of members. But our strategy is not predicated on endorsements in any state."

The four new offices, combined with existing offices in central Las Vegas, Elko and Reno, give the Obama campaign a total of seven in Nevada, more than twice as many as any other candidate.

Two Obama supporters, state Sen. Steven Horsford of Las Vegas and Assemblyman Kelvin Atkinson of North Las Vegas, will be on hand Saturday for the opening of the North Las Vegas office, at 2 p.m. at 4080 N. Martin L. King Blvd., south of the intersection with Craig Road. The Carson City office will be opened by Assemblywoman Sheila Leslie or Reno.

The campaign also plans a statewide canvassing effort Saturday morning to commemorate the fifth anniversary of the Senate vote authorizing the Iraq war. Obama at the time was not yet a U.S. senator, but as an Illinois state senator running for higher office he opposed the war.

Other Democratic campaigns in Nevada agreed with both ideas, that it is too soon to tell who has the advantage in the state and that grass-roots organization will be the key to winning the caucuses. They just argued that they, rather than Obama, were best situated to capitalize on those factors.

"I don't know if the locations of offices are necessarily an indication of how deep you are in the community," said Hilarie Grey, a spokeswoman for U.S. Sen. Hillary Clinton of New York. "We have organizers in every nook and cranny of the state. We are getting great reactions everywhere we go. That's what it's all about, going precinct by precinct and getting people committed to you to turn out in the caucus."

The Clinton campaign also has a statewide canvas scheduled for Saturday, she said.

A spokesman for former U.S. Sen. John Edwards of North Carolina pointed out that Edwards trailed in polls in late 2003 and former Vermont Gov. Howard Dean seemed to have a commanding lead.

"Senator Edwards surged ahead late in a caucus state in Iowa, which is what we expect to do here in the caucus state of Nevada," Adam Bozzi said.

"It's about the depth of your support and the ability to organize your supporters to come out on a Saturday and stand up for you," he said.

Contact reporter Molly Ball at mball@reviewjournal.com or (702) 387-2919.