WASHINGTON — Increasingly acting like the Democratic presidential nominee, Barack Obama is beginning to vet potential running mates, laying plans to take control of the party's campaign apparatus and trying to overcome vulnerabilities exposed in the prolonged primary season.
Obama has not asserted the nomination is his, for fear of offending supporters of his rival, Hillary Rodham Clinton, who lags Obama among delegates to the party's nominating convention but shows no signs of conceding the race. Still, his recent campaign stops and administrative moves show that his central focus is the November election.
The campaign has tapped Jim Johnson, an Obama fundraiser, to oversee the screening of potential vice presidential candidates, according to campaign aides.
Johnson, vice chairman of the merchant bank and private equity fund Perseus, worked as a top aide to then-Vice President Walter F. Mondale. He helped Mondale vet potential running mates in Mondale's unsuccessful 1984 presidential campaign and played a similar role for Massachusetts Sen. John F. Kerry, the 2004 Democratic nominee.
"He's been through this VP thing many, many times," Mondale said.
Johnson "worked for me in a key position in the White House," Mondale noted. "He knows what it is, because he lived there."
As the nominee, Obama would gain effective command of the party's campaign machinery, centered at the Democratic National Committee in Washington. Campaign staff indicated that Obama's liaison to the DNC would be a trusted campaign aide, Paul Tewes, who ran Obama's campaign in Iowa, where the candidate scored his first and arguably most important victory.
Last week, DNC officials traveled to the Illinois senator's headquarters in Chicago to talk through how the campaign and the DNC might join forces. The officials discussed strategy, fundraising, opposition research and communications, according to people familiar with the meeting.
The party has held similar meetings with Clinton's campaign, in case the New York senator wins the nomination -- a prospect that has become increasingly unlikely in recent weeks.
With only three more primary contests remaining -- in Puerto Rico on June 1 and South Dakota and Montana on June 3 -- Obama is also moving to solidify his position in November's likely battleground states.
He is in the midst of a three-day swing through Florida, where he has sought to allay fears among some Jewish voters that he is not sufficiently supportive of Israel. On Memorial Day, Obama and his wife, Michelle, are scheduled to visit New Mexico, also considered a swing state.
"It makes sense to bring the party together, to merge all the Democratic Party infrastructure, to start the healing, and to visit states like Florida that he hasn't had a chance to visit much," said New Mexico Gov. Bill Richardson, an Obama supporter.
"It makes sense to do this, because he's going to be the nominee," Richardson added.
Obama's preparations on this score are a delicate matter. He does not want to appear to be pushing Clinton from the stage, so he can remain well-positioned to win the votes of her supporters in the general election.
Clinton insists she has a viable path to the Democratic nomination. In a conference call with reporters Thursday, her top strategists argued that if party leaders restored the disputed delegates from Florida and Michigan, she could wrest the nomination from Obama.
Obama aides are keeping the hunt for a running mate a closely guarded effort. Obama has not shared his thinking on how much weight he will give to calls from some Democrats to make Clinton the vice presidential nominee.
Other potential choices include Richardson and former Sen. John Edwards of North Carolina. Both ran against Obama for the nomination but later dropped out and endorsed him.
Others who may be on Obama's list include Kansas Gov. Kathleen Sebelius and three senators: Joseph R. Biden Jr. of Delaware, who also ran for president this year; Claire McCaskill of Missouri; and Jim Webb of Virginia.
During a visit to a Boca Raton synagogue Thursday, Obama got an indirect question about whether he might name Clinton as his vice president.
"Will you be willing to consider everyone a possible running mate, even if his or her spouse is a pain in the butt?" one person asked.
After he and the crowd stopped laughing, Obama cautioned that it was too soon to talk about possible vice presidential nominees. "Two weeks from now, we will know who the Democratic nominee is going to be, so I don't want to jump the gun," he said.
But he noted that one of his heroes, Abraham Lincoln, stocked his administration with rivals, and he said he would be willing to do the same.
While in Florida, Obama has made an effort to address weaknesses that have emerged during his campaign fight with Clinton. One point of concern is Jewish voters.