WASHINGTON — In the two weeks since Barack Obama became the presumptive Democratic nominee, John McCain has demonstrated a knack for driving the daily political debate, forcing his opponent to respond to a challenge to meet in town hall debates, accusing him of being "delusional" about terrorism and saying he flip-flopped on public financing for his campaign.

But even as McCain's strategists claim tactical victories, Republicans outside the campaign worry that underlying weaknesses in its organization and message are costing him valuable time to make the case for his own candidacy.

Allies complain that the campaign has offered myriad confusing themes that lurch between pitching McCain as a committed conservative one day and an independent-minded reformer the next, while displaying little of the discipline and focus that characterized President Bush's successful campaigns.

Several Republican supporters of the presumptive nominee said they were puzzled by a series of easily avoidable mistakes, including sloppy political stagecraft and poorly timed comments that undercut McCain's reputation as a maverick.

The grumbling intensified last week when McCain launched a television commercial declaring that he had "stood up" to Bush on global warming, on the same day he traveled to Houston to call for lifting the federal ban on offshore drilling.

Critics said the ad's message about the differences between McCain and Bush was lost when Bush endorsed the same coastal drilling proposal the next day.

"I'm baffled that the McCain guys have somehow managed to take a guy who practically had 'reform' tattooed to his forehead and turned him into the bastion of the status quo," said one Republican strategist, who like others spoke on the condition of anonymity.

The veteran strategist, who has not been asked to join the campaign, said the "devastating me-too chorus from Bush and (Vice President Dick) Cheney" on oil drilling is a "great example of the schizophrenia that surrounds their campaign."

Senior aides to McCain reject such criticisms as "armchair quarterbacking." They cite recent polls that show McCain only slightly behind Obama despite record low approval ratings for Bush and congressional Republicans. A Washington Post poll on Tuesday showed McCain trailing Obama by six percentage points.

"We feel very good about where our campaign is right now, and John McCain is running very competitively in an electoral environment that is otherwise very challenging for Republicans," said McCain spokesman Tucker Bounds.

The campaign faced inquiries Saturday from Democrats, who continued to raise legal questions about McCain's Friday trip to Canada, where he spoke at a $100-per-person luncheon and then met with business executives privately. Democrats demanded to know whether McCain's campaign received any money from foreign sources, since that would be illegal under U.S. law.

McCain spokeswoman Jill Hazelbaker said the $100 tickets sold by the Economic Club of Canada did not benefit the campaign and that the meeting with executives was not a fundraiser. Mark Adler, the chief executive of the club, said in an e-mail that "all ticket revenue was used to stage the event and luncheon" and that "the McCain campaign in no way benefited financially from this event." Hazelbaker said flatly that neither of the events was "a campaign event."

Democratic officials questioned why, then, the campaign paid for the Canada trip and brought reporters along. And they said the event with executives could qualify as an in-kind contribution since some of McCain's comments there were reportedly political in nature.

The McCain campaign did get a bit of good news last week: It raised about the same amount of money in May as the Obama campaign did, and the Republican trails by only a little in cash on hand.

But as the criticisms mount, McCain has begun to make some changes to his operation and adapt to a general-election race against a well-funded opponent with a large and sophisticated political organization.

At the request of campaign manager Rick Davis, senior adviser Steve Schmidt will leave McCain's side on the trail and return to headquarters for what a source said will be a "much greater operational role" in the campaign. A former aide to Cheney, Schmidt managed California Gov. Arnold Schwarzenegger's re-election campaign. His portfolio will expand to include strategy, communications, policy, scheduling and other areas, the campaign source said.

Former Bush communications director Nicolle Wallace joined McCain's campaign as a senior strategist in May. This week, she spent time with McCain on his plane for the first time. Matt McDonald, another veteran of the Bush and Schwarzenegger teams, has also been added to the campaign.

Still, McCain's campaign continues to be led by a relatively insular group of advisers who stuck by him during the darkest times of his primary campaign. Interviews with lawmakers and Republican operatives last week revealed concern about their strategy.

"The biggest mistake they are making, they are trying to walk this tightrope between creating distance from Bush and not angering the base," said a Michigan Republican operative who described himself as nervous about McCain's chances of victory in that swing state.

"He's got to highlight the things that used to make conservatives pull their hair out," said the Michigan operative. "I don't think they are doing that very well."

Another Republican strategist, who worked for a rival GOP campaign during the primary and has ties to Bush's political team, said the McCain team has "not really figured out" how to present McCain to voters: as an experienced conservative leader or a reformer who wants change.

"To them, McCain is inevitable," the GOP strategist said. "They are good on the opposition research side of forcing the agenda. But who John McCain is and what he stands for — it's a little hard to connect all the dots."

The problem has played out in the campaign's changing slogans. On June 3, a much-ridiculed green background behind McCain sported the new phrase "A Leader We Can Believe In," a play on Obama's message of "Change We Can Believe In." But just a few days later the campaign ditched that slogan and replaced it with "Reform. Prosperity. Peace."

McCain or his aides seem to have undercut their message at times.

On the same day that McCain sought to respond to higher gas prices by calling for an end to the drilling moratorium, his senior policy adviser, Douglas Holtz-Eakin, told reporters in a conference call that the move would not boost oil supplies or bring down gas prices in the immediate future.

A three-day trip to Florida in early June was overshadowed by questions about McCain's opposition to Everglades funding and a catastrophic insurance fund. His comment last week that it's "not important" if troops remain in Iraq distracted from a Philadelphia town hall event that day.

Still, some McCain allies believe voters will turn to him if Obama's initial luster fades. "This was a guy who was above politics, and it's becoming clear that he's just another politician," Rep. Tom Davis, R-Va., said of Obama. "For most voters, McCain is a safe haven."

"To be even in a ... horse race, I find that good news," said Rep. Jeb Hensarling (Texas), who chairs the Republican Study Committee. "He's clearly the one Republican, I believe, who can be victorious in November."

Rep. Jack Kingston, R-Ga., said the race is a draw, adding that McCain has the edge on terrorism and foreign policy while Obama leads on the issue of change. "They're just in the ring, circling each other, and neither is pulling the punches they might want to," he said.

Kingston said McCain does need to focus on certain elements of a modern campaign, such as his Internet operation, if he hopes to stay close with Obama. "Obama and his friends at MoveOn.org, they own the Internet right now," he said.

McCain's people continues to be aggressive in their critique of Obama, pressing what they see as a clear advantage. In a memo released to the news media Friday, Schmidt accused Obama of using words that are "empty of meaning" and of putting rhetoric above policy.

The memo said that Obama broke his word on a promise to participate in the public financing system and that he had gone back on his pledge to debate "anywhere, anytime" by refusing to meet McCain in town hall meetings every week this summer.

Davis, who is leaving Congress after this year, said McCain has the advantage of being a well-defined brand in the minds of many voters. And he said there is plenty of time left to burnish it.

"This is still skirmishing. They are still sparring. The main event won't start until after the conventions," Davis said. "This still has a long way to go. People forget that."