(CNN) - President Barack Obama is planning a major campaign swing out West in the final days leading up to the midterm election because party leaders have privately come to the conclusion that control of the Senate could come down to the fate of three highly vulnerable incumbents in that region, according to senior Democratic officials.
The three full days of campaigning in late October will focus on trying to save incumbent Sens. Patty Murray of Washington, Barbara Boxer of California and Majority Leader Harry Reid of Nevada, with the senior Democratic officials telling CNN that party leaders are privately growing particularly worried about whether Reid can survive.
Obama will begin the Western campaign swing on October 20 in Portland, Oregon, to help support Democrat John Kitzhaber in the hotly contested, open-seat gubernatorial race. Kitzhaber, the state's former governor, is neck and neck with Republican Chris Dudley, a former NBA player.
Later on October 20, Obama will travel to Seattle to lend a hand to Murray, who is locked in a dead heat with Republican Dino Rossi, with some polls suggesting the incumbent is trailing slightly. This will be Obama's second trip in recent months to try and help shore up Murray.
Then, on October 21, Obama heads to San Francisco to campaign with Boxer, who is locked in a tough battle with Republican businesswoman Carly Fiorina. The senior Democratic officials say they feel good about Boxer's prospects because some polls show her widening her slight lead, but the officials note that in this tough year for Democratic incumbents virtually no lead is safe.
On October 22, Obama will head to Las Vegas for a previously announced Democratic National Committee rally to whip up support for various candidates, but the senior officials said the president also will stay overnight in order to do some fundraising for Reid, who is in the political fight of his life with Republican Sharron Angle, a Tea Party favorite.
A new CNN/Time/Opinion Research Corporation poll released Wednesday found that Angle is leading Reid 42 percent to 40 percent among likely voters in Nevada, with 10 percent saying they will vote for none of the candidates listed, a rare option that voters in the state have. Seven percent of the people are supporting Scott Ashjian, who is running as the actual Tea Party candidate but is shunned by many in the grass-roots conservative movement.
Angle's two-point advantage over Reid is well within the survey's sampling error, and Angle had a one-point lead in a CNN/Time poll conducted in September.
But senior Democratic Party officials privately told CNN they are growing increasingly concerned that Reid just can't seem to get past the low- to mid-40's in various polls, despite weeks and weeks of making his case that Angle is an extreme conservative who is too far out of the mainstream.
These same senior officials said they are also worried the percentage of people in Nevada saying they will vote for the "none of the above" option is decreasing. Democratic officials have long believed that people who take the time to vote for none of the above are angry at Washington and would never vote for Reid, so they could be pulling votes away from Angle by voting for none of the above.
Since the number of those voters now seems to be going down in a number of polls, Democratic officials fear that some of these voters are coming home to Angle out of fear that they will help re-elect Reid if they vote for none of the above instead of the Republican.
But a senior Reid adviser said it's hardly a surprise to the senator's campaign team that he has an uphill battle, and they're still confident of victory.
"There's no news in this recent series of polls. We've always known it would be close," said the Reid adviser. "But in the end he is going to win. The ground game is going to come through, and Reid is going to be able to pull it out."