Barack Obama is getting an early taste of how the verbal fireworks and talking points from his bitter primary battle against Hillary Clinton could be turned against him as he enters the general election race.

The Illinois senator is taking flak for an adviser's ties to a controversial lender, and to hold Obama's feet to the fire, John McCain's campaign is citing the Obama team's own words from the primary.

The adviser in question is Jim Johnson, who is heading up Obama's three-person running-mate search team.

McCain called it a "contradiction" for Obama to be associated with Johnson after The Wall Street Journal reported that Johnson received favorable loan terms from Countrywide Financial Corp., a sub-prime lending company Obama has criticized.

The reaction from Republicans only underscores how carefully Obama will have to tread in hand-picking anyone affiliated with his campaign. Even a trace of hypocrisy from the Democratic candidate promising reform at all levels seems to be instant fodder for his GOP critics.

One week after clinching the Democratic nomination, Obama on Tuesday said the criticism is all part of a "game," and that, in this instance, he can't be expected to screen his search committee members for their mortgages.

"I would have to hire the vetter to vet the vetters," he said, adding that those search team members are unpaid volunteers. "These aren't folks who are working for me."

The McCain campaign scoffed at that assessment.

"Of course Jim Johnson works for him," said Carly Fiorina, former Hewlett-Packard CEO now serving as McCain's liaison to the Republican National Committee. "Barack Obama understands full well that in presidential politics, any associate -- but particularly one who is working directly for the candidate -- is going to be scrutinized."

She called Obama's explanation Tuesday "naïve."

The McCain campaign also dug up statements made by Obama strategist David Axelrod in which he criticized Clinton for having a connection to Countrywide.

In the statements to MSNBC, made after Clinton strategist Mark Penn stepped down in early April, Axelrod said: "She's stuck with (Penn) through the revelation that his firm was working for Blackwater and working for Countrywide, and ... so it's kind of stunning."

McCain spokeswoman Jill Hazelbaker told FOX News the statement reflects the "hypocrisy" inside the Obama campaign.

Capitalizing on the jabs and swipes of the primary race, the Republican National Committee also is posting and circulating videos showing Clinton criticizing Obama for being inexperienced and for associating himself with unsavory characters.

But if the McCain campaign is going to use primary battle rhetoric against the presumptive Democratic nominee, McCain can probably expect the same treatment.

Geraldine Ferraro, Walter Mondale's 1984 running mate, said those tactics are inevitable.

"If it's used by McCain, that's just typical politics, and we assume the Obama campaign will do the exact same thing," said Ferraro, who supported Clinton during the primary and has not endorsed Obama.

Ferraro was also vetted in 1984 by a Johnson team, and she said Johnson is more than qualified to continue helping Obama.

"I don't think it should be overblown," she told FOXNews.com. "This is a person who knows the job, who knows how to do it. And you pick the person who has experience doing it."

But the scrutiny continued Tuesday for Johnson, a long-time Washington insider and former CEO of Fannie Mae. He is also on the board of directors for Goldman Sachs and formerly handled VP vetting for John Kerry in 2004, as well as Mondale in 1984.

National Review Online, for instance, reported that a federal investigation completed two years ago found Johnson made use of a program available to "only very senior Fannie Mae executives" that enabled him to defer portions of his compensation. As a result, Fannie Mae reportedly was able to withhold from the public the size of Johnson's 1998 compensation, putting the figure at $6-7 million when it was actually $21 million.

Politico.com reported that five corporations whose CEO compensation committees were chaired by Johnson -- and all of which approved hefty CEO compensation packages -- drew criticism from two watchdog groups that monitor CEO performance and compensation.

One of them dubbed Johnson a "problem director,"as has the AFL-CIO, most of whose member unions have endorsed Obama.

The Wall Street Journal reported over the weekend that Johnson received more than $7 million in loans from Countrywide Financial Corp. The Journal reported Johnson received at least two loans at below-market rates as a result of a relationship he had with the company's CEO Angelo Mozilo. The Journal reported there was nothing apparently illegal about the loan terms.

But the ties came under fire since Obama has criticized Countrywide on the stump. The company's top executives were accused in March of exacerbating the home mortgage crisis.

Obama said at the time in a statement, "We should be reprimanding them, not rewarding them. Rewarding their bad behavior just encourages others to pursue the same kinds of irresponsible practices that led us into this financial mess in the first place."

The Obama campaign attempted to turn the tables on McCain on Tuesday, circulating an ABC News report highlighting the past lobbying work of Arthur Culvahouse, a former Reagan official advising McCain in his running mate hunt.

McCain has taken his lumps for the lobbying ties of some of his staff members, as he tries to enact a strict conflict-of-interest policy forbidding registered lobbyists from being part of the campaign.

FOX News' James Rosen, Judson Berger and Bonney Kapp contributed to this report.