WASHINGTON - Jim Johnson, the most experienced hand guiding Democrat Barack Obama's vice presidential search, stepped down yesterday as Republican criticism of his home-mortgage deals became a distraction for a candidate who eschews Washington insider influence.

Johnson's resignation leaves the job of vetting Obama's No. 2 at least temporarily in the hands of two other prominent Democratic attorneys who had been working with him on the search: former Deputy Attorney General Eric Holder and Caroline Kennedy, daughter of President John F. Kennedy.

The campaign declined to answer whether Obama would replace Johnson, who led the vetting for Democratic nominees John Kerry in 2004 and Walter Mondale in 1984. Obama, in a statement, said he was grateful to Johnson for his service.

"Jim did not want to distract in any way from the very important task of gathering information about my vice presidential nominee, so he has made a decision to step aside that I accept," Obama said. "We have a very good selection process under way, and I am confident that it will produce a number of highly qualified candidates for me to choose from in the weeks ahead."

Johnson, the former chairman of mortgage lender Fannie Mae, came under fire from GOP candidate John McCain and the Republican Party after the Wall Street Journal reported Saturday that Johnson got mortgage loans with help from the CEO of Countrywide Financial Corp.

McCain had accused Obama of hypocrisy for speaking out against Countrywide's role in the subprime mortgage crisis.

Johnson's resignation lets Obama move on with the vetting process without the criticism surrounding him, but it also could make it appear that the campaign quickly caved under pressure. The resignation touched off accusations between the two campaigns about which candidate has more tainted advisers and better judgment about whom to surround himself with.

Obama's campaign has had varying responses when controversy has focused on those around him. Foreign-policy adviser Samantha Power left within hours of calling Hillary Rodham Clinton a "monster." Obama was initially reluctant to disavow his pastor, Jeremiah Wright, after video of racially explosive sermons emerged. And he kept leading economic adviser Austan Goolsbee on board amid controversy surrounding his private comments on free trade.

At least five McCain staffers have left his campaign in the wake of a Democratic uproar over McCain's connections to lobbyists. McCain responded by banning registered lobbyists serving his campaign but has defended two of his top advisers - Rick Davis and Charlie Black - who left their lobbying jobs to work for his presidential bid.

On Tuesday, Obama said Johnson had a "discrete task" and was performing it well. He suggested the Countrywide connection was not a problem since Johnson was an unpaid volunteer and had not been assigned to work in a future administration.

"I am not vetting my VP search committee for their mortgages," Obama said at the time.