Talk Elections

Senator Barack Obama has all but settled on his choice for a running mate and set an elaborate rollout plan for his decision, beginning with an early morning alert to supporters, perhaps as soon as Wednesday morning, aides said.

Mr. Obama’s deliberations remain remarkably closely held. Aides said perhaps a half-dozen advisers were involved in the final discussions in an effort to enforce a command that Mr. Obama issued to staff members: that his decision not leak out until supporters are notified.

Mr. Obama had not notified his choice — or any of those not selected — of his decision as of late Monday, advisers said. Going into the final days, Mr. Obama was said to be focused mainly on three candidates: Senator Evan Bayh of Indiana, Gov. Tim Kaine of Virginia and Senator Joseph R. Biden Jr. of Delaware.

Some Democrats said they still hoped that he would choose Senator Hillary Rodham Clinton of New York, or Gov. Kathleen Sebelius of Kansas, who has been under steady consideration by Mr. Obama’s campaign.

By all indications, Mr. Obama is likely to choose someone relatively safe and avoid taking a chance with a game-changing selection. A similar strategic choice now faces Mr. Obama’s Republican rival, Senator John McCain of Arizona, who has been under pressure from some Republicans to make a more daring choice.

Mr. Obama’s advisers said he all but reached his decision while on vacation in Hawaii. They said it was the end of what proved to be an unexpectedly intense process, condensed because he did not want to start actively vetting potential running mates before Mrs. Clinton quit the race in June.

By contrast, Mr. McCain, who had wrapped up the Republican nomination months earlier, began his process in late spring.

That gave Mr. Obama’s team of lawyers less time to review candidates, and several Democrats said it appeared that the list of candidates who were deeply vetted was limited to about a half-dozen people. (Campaigns typically check the background of candidates who are not necessarily in play, as a way of gaining favor with various constituencies or to keep the other party off balance.)

The team of advance workers and aides involved in planning the rollout — timed to galvanize Democratic voters as Mr. Obama heads to Denver next week for the party convention — have not been told who Mr. Obama will be selecting.

If all goes according to plan, the announcement will be made with text and e-mail messages to supporters early in the morning, in time to capture coverage on the morning news shows and take advantage of a full day’s news cycle.

Mr. Obama and his running mate will begin, perhaps that day, a visit to swing states. Plans call for them to be on the trail together for much of the time between the day of the announcement and the day Mr. Obama arrives in Denver, a week from Wednesday, but their most intense campaigning together will come after the convention.

Mr. Obama’s schedule calls for him to awaken on Tuesday in Orlando, Fla., and by the end of the day be in Raleigh, N.C. By Wednesday, he is scheduled to be in Virginia. The Obama campaign has cautioned against reading anything into his schedule, saying it could be changed in an instant to accommodate the plan to introduce the running mate.

Aides said the announcement would come at the earliest on Wednesday morning.