WASHINGTON (CNN) -- A key member of Sen. Barack Obama's vice presidential search team, Jim Johnson, is stepping down after criticism over a mortgage he received, the Obama campaign said Wednesday.
"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," the presumed Democratic presidential nominee said.
Republicans had been hammering Johnson since The Wall Street Journal reported Saturday that he received a good deal on a mortgage from Countrywide because of his friendship with Angelo Mozilo, the company's CEO.
Obama has criticized Countrywide in connection with the subprime mortgage crisis.
Tucker Bounds, a spokesman for Sen. John McCain, the presumed GOP presidential nominee, said Johnson's resignation "raises serious questions about Barack Obama's judgment. ... By entrusting this process to a man who has now been forced to step down because of questionable loans, the American people have reason to question the judgment of a candidate who has shown he will only make the right call when under pressure from the news media. iReport.com: Who should be VP?
"America can't afford a president who flip-flops on key questions in the course of 24 hours. That's not change we can believe in," Bounds added.
Responding to Bounds, Obama spokesman Bill Burton said, "We don't need any lectures from a campaign that waited 15 months to purge the lobbyists from their staff and only did so because they said it was a 'perception problem.'
"It's too bad their campaign is still rife with lobbyist influence and doesn't see a similar 'perception problem' with the man currently running their own vice presidential selection process," Burton said.
Arthur Culvahouse, a member of the Reagan administration, leads McCain's search team. According to The Associated Press, Culvahouse, a partner at international law firm O'Melveny & Myers, has been a lobbyist for Fannie Mae and Lockheed Martin.
The Wall Street Journal reported that Johnson received more than $7 million in home loans from Countrywide, made available through a program for friends of the company's chief executive officer.
For several days, Obama pushed back against the attacks on Johnson, the first person he named to head his search team.
"I am not vetting my VP search committee for their mortgages," Obama said Tuesday in St. Louis, Missouri, where he was campaigning.
"This is a game that can be played -- everybody who is tangentially related to our campaign, I think, is going to have a whole host of relationships. I would have to hire the vetter to vet the vetters," he said.
A Republican Party spokesman called Obama "naive" and "hypocritical" after Obama's remarks Tuesday, before Johnson stepped down.
"Barack Obama's assertion that he won't vet his own senior aides is totally inconsistent with his rhetoric," said Alex Conant, a Republican National Committee spokesman.
Johnson, a former CEO of Fannie Mae, was one of three people on Obama's search team, alongside former Deputy U.S. Attorney General Eric Holder and Caroline Kennedy, daughter of President John Kennedy.
The Obama campaign has not announced a replacement.
Johnson and Holder met members of Congress on Tuesday to discuss possible running mates for Obama. Watch a report on the VP buzz »
The Republican Party broadened its attacks on Obama in the wake of Johnson's dismissal.
"If Barack Obama is concerned his campaign's ties to special interests are distracting from his VP search and message, why is Eric Holder still on his search committee?" party spokesman Alex Conant asked.
"Obama's hypocritical attacks show he can't stand up to his own standard -- and that he just isn't ready to make change."
The Republican Party accuses Holder of being a key player in the controversial pardon of fugitive financier Marc Rich by President Clinton in the final days of his presidency.