By Jim Rutenberg

updated 11:19 p.m. ET July 30, 2008

WASHINGTON - After spending much of the summer searching for an effective line of attack against Senator Barack Obama, Senator John McCain is beginning a newly aggressive campaign to define Mr. Obama as arrogant, out of touch and unprepared for the presidency.

On Wednesday alone, the McCain campaign released a new advertisement suggesting — and not in a good way — that Mr. Obama was a celebrity along the lines of Britney Spears and Paris Hilton. Republicans tried to portray Mr. Obama as a candidate who believed the race was all about him, relying on what Democrats said was a completely inaccurate quotation.

The Republican National Committee began an anti-Obama Web site called “Audacity Watch,” a play on the title of Mr. Obama’s book “The Audacity of Hope.” And, in a concerted volley of television interviews, news releases and e-mail, campaign representatives attacked him on a wide range of issues, including tax policies and energy proposals.

The moves are the McCain campaign’s most full-throttled effort to define Mr. Obama negatively, on its own terms, by creating a narrative intended to turn the public off to an opponent.

Bush brain trust lends a hand
Although Mr. Obama has been under an intense public spotlight for the last year, he is still relatively new on the national scene, and polls indicate that for all the enthusiasm he has generated among his supporters, many voters still have questions about him, providing Republicans an opening to shape his image in critical groups like white working-class voters between now and Election Day.

Mr. McCain’s campaign is now under the leadership of members of President Bush’s re-election campaign, including Steve Schmidt, the czar of the Bush war room that relentlessly painted his opponent, Senator John Kerry of Massachusetts, as effete, elite, and equivocal through a daily blitz of sound bites and Web videos that were carefully coordinated with Mr. Bush’s television advertisements.

The run of attacks against Mr. Obama over the last couple of weeks have been strikingly reminiscent of that drive, including the Bush team’s tactics of seeking to make campaigns referendums on its opponents — not a choice between two candidates — and attacking the opponent’s perceived strengths head-on. Central to the latest McCain drive is an attempt to use against Mr. Obama the huge crowds and excitement he has drawn, including on his foreign trip last week, by promoting a view of him as more interested in attention and adulation than in solving the problems facing American families.

‘The biggest celebrity in the world’
“I would say that it is beyond dispute that he has become the biggest celebrity in the world,” Mr. Schmidt said in a conference call with reporters on Wednesday. “The question that we are posing to the American people is this: ‘Is he ready to lead yet?’ And the answer to the question that we will offer to the American people is: ‘No he is not.’ ”

Video   Campaigns respond July 31: TODAY’s Matt Lauer talks to Nicolle Wallace, an aide for John McCain, and Robert Gibbs, a spokesman for Barack Obama, about the new McCain ad. Today show

Mr. McCain’s more focused assault comes after one of his worst weeks of the general election campaign, when he seemed to fumble for a consistent, overarching critique of Mr. Obama, who winged around the Middle East and Europe. Mr. McCain’s advisers continue to look for ways to bring more discipline to his message, and are being urged by some supporters to cut back the frequency of his question-and-answer sessions with reporters, a staple of his campaign but one that occasionally yields unscripted moments, misstatements and off-the-cuff pronouncements that divert attention from the themes he is trying to promote.

Some in GOP recoil at tactics
The intensity of the recent drive — which has included some assertions from the McCain campaign that have been widely dismissed as misleading — has surprised even some allies of Mr. McCain, who has frequently spoken about the need for civility in politics. The sentiment seeped onto television on Wednesday with Andrea Tantaros, a Republican strategist, saying on MSNBC that the use of Ms. Hilton in Mr. McCain’s commercial was “absurd and juvenile,” and that he should spend more time promoting his own agenda.

More from NYTimes.com Analysis: Campaign Promises on Iraq War Muted by Reality In Banking, Top Obama Aide Made Money and Connections Long Road Behind Him, Richardson Gets a Post Economic Stimulus Plan Tied to Energy Savings External links

Mr. Obama’s campaign seized on those concerns, trying to turn the tables by portraying Mr. McCain as cranky and negative. The Democratic National Committee called Mr. McCain “McNasty.” Late Wednesday Mr. Obama released a counter advertisement citing editorials critical of Mr. McCain’s latest volley of attacks and featuring an announcer who says, “John McCain, Same old politics, same failed policies.”

Asked by reporters about Mr. McCain’s new advertisement, Mr. Obama said, “I do notice that he doesn’t seem to have anything to say very positive about himself.”

MORE FROM THE NEW YORK TIMES

The New York Times Section Front

NYT: Obama plots green jolt to economy NYT: Obama faces delicate task with CIA NYT: Pardon back in focus for Justice nominee NYT: A team for a foreign policy shift NYT: Bill Clinton agrees to reveal donors NYT: Bush-Obama battle over safety rule NYT: GOP committee keeps heat on Obama NYT: For lobbyists, turnover not a downturn NYT: Clinton, Obama achieve détente NYT: Obama tilts to center, inviting a clash of ideas The New York Times Section Front