WASHINGTON - George W. Bush had two roles to play last week.

There was the president who was under intense pressure to calm a nation nervous about a plummeting stock market and corporate scandals. He responded by warning executives not to engage in deceitful accounting to inflate profits.

And then there was the former Texas businessman who once served on the board of a company that overstated profits. He responded by going on the defensive.

"It was just an accounting firm making a decision, along with corporate officers, as to how to account for a complex transaction," Bush said at a news conference.

Such was the tightrope Bush walked in one of the toughest weeks of his presidency. Questions about the health of corporate America gripped attention and spooked the financial markets. Bush tried to restore confidence. But the more he made business abuses an issue, the more he was pressed about his actions a decade ago.

In a speech on Wall Street, Bush declared his desire to usher in an era of corporate responsibility. However, he declined to take responsibility for his role in questionable business activities, some of which helped him amass his personal fortune.

Bush's image as a president with close ties to corporate America received scant attention when the war on terrorism dominated headlines. Now, with accounting scandals and economic health topping the nation's agenda, Democrats hope they have found an issue that could leave Republicans vulnerable.

If corporate ethics remains a hot topic, Bush will have to settle on a strategy: Should he continue to play down his corporate past while trying to persuade Americans he won't tolerate business abuses that threaten the economy? Or should he step forward and detail his corporate activities in Texas to solidify his credibility as a reformer?

Senate Majority Leader Tom Daschle said it would be hard for Bush to criticize business executives until his past conduct is explained.

"As long as those outstanding questions are there, it puts the president in a difficult position, an uncomfortable position," said Daschle, a South Dakota Democrat.

To be sure, analysts say, if the economy - and the financial markets - improve, voters in the midterm elections will be less likely to punish the party in the White House. And Bush might suffer little damage from the questions being raised now.

But should ordinary Americans turn fearful about their financial health, Democrats might argue to voters that Bush failed to rescue the economy because he was unwilling to take on his corporate allies.

Judged on performance

"Americans judge presidents not on image, but on performance," said Andrew Kohut, director of the Pew Research Center for the People and the Press. "If things get better, he'll be credited with helping. If the stock market continues to languish, the chances of chipping away at his image get better."

Kohut added: "Any time the condition of the economy is being threatened by scandal, and the stock market reacts, the president is not having a good week no matter what he says."

Making matters worse for the White House is Vice President Dick Cheney's ties to Halliburton Co., an energy services and construction company that is being investigated by the Securities and Exchange Commission and is being sued by shareholders for its accounting practices. Cheney served as chief executive officer of Halliburton before becoming vice president.

"Both Bush and Cheney must be thinking to themselves, 'Mother told me there'd be days like this,'" said Jack Pitney, a political science professor at Claremont McKenna College in California.

The president, Pitney said, is unlikely to face political damage from his actions in Texas unless there are new revelations. Bush's standing this year, and his party's success in November, Pitney suggested, will depend mostly on the health of the economy. Still, the professor said, he was surprised that Bush, even if he did nothing unethical as a businessman, did not even acknowledge at his news conference the questionable nature of his dealings then.

"He could have said, 'I'm not sure of all the details, but it's my responsibility, and I made a mistake,'" Pitney said. "People like to hear leaders take responsibility."

White House reaction

At the White House, officials scurried all week to explain Bush's business activities and to insist that he was not being hypocritical in scolding those who engage in corporate malfeasance.

Aides argued that Bush's business background was old news that had been put to rest in Bush's previous campaigns and that the SEC had cleared him of any wrongdoing.

"After a week of noise about nothing," said Ari Fleischer, Bush's spokesman, "people are seeing a scandal-seeking Washington that's out of touch with a solution-seeking nation."

But the president was also becoming isolated last week by Republicans in Congress. Not satisfied with Bush's plans for corporate reform, Republicans began to back steps proposed by Democrats that were far tougher that what Bush had proposed. The more aggressive stance by those in his party served to forge a perception that Bush was offering mostly rhetoric and was not really prepared to crack down on abuses.

Some Republicans defended him. Sen. Rick Santorum of Pennsylvania, for example, called questions about the president's past "part of the politics that gets played up here, which is if you can't find fault with someone's policies, go after them personally."

Embracing reforms

Yet it was clear that most Republicans were eager to keep pace with Democrats in embracing reforms and distancing themselves from the debacles at Enron, WorldCom and other companies and from the resulting slide on Wall Street.

"We're just out there talking about it as aggressively as they are," said Sen. Bill Frist, a Tennessee Republican. "We are equally aggressive both in the talk but also in the legislation."

Even some conservatives who typically back Bush said he did not seem sure-footed at his news conference, where he discussed corporate ethics and seemed impatient when pressed about his past.

"He just didn't seem like he was prepared," said Michael Franc, vice president for government relations at the conservative Heritage Foundation.

Franc expressed concern that, if the stock market continues to fall between now and the November elections, Democrats would portray Bush as beholden to big business and as unwilling to back needed reforms.

"That would be an ad campaign that could resonate," Franc said.

Bush's approval ratings remain high - above 70 percent in most polls. There are signs of trouble, though. A shrinking majority of people, for example, say they approve of his handling of the economy.

And in a USA Today/Gallup survey taken a week ago, 46 percent said they thought Bush was more intent on protecting corporations' interests than those of ordinary Americans.

Some Americans have long expressed concern that Bush is closely tied to businesses. But the president has generally overcome such worries. With his corporate experience, and as the first president to hold a master's degree in business administration, he has often cast himself as someone able to reform government and make it more efficient.

But Bush's experience seemed more of a liability last week. He faced the growing perception that as he amassed his personal wealth in Texas, he was involved in some of the practices that he now says need to be wiped out.

For example, Bush called for an end to company loans to corporate officers. Yet, in the 1980s, Bush received generous loans from Harken Energy Corp., where he was a board member, to help him buy company stock.

In 1990, Bush sold Harken shares in a move that earned him $850,000. Two months later, Harken reported a loss, and its share price tumbled. Bush said that when he sold his shares, he did not know Harken was about to report a big loss. Had he known, he could have been guilty of illegal insider trading.

Not fully explained

But to date, he has not fully explained why he was months late in reporting his stock sale to the SEC. The SEC investigated the matter while Bush's father was president and said it found no evidence of wrongdoing.

In addition, the president served on Harken's board in 1989, when the company sold off a subsidiary in Hawaii and immediately claimed a $7.9 million profit at a time when the company was struggling.

The SEC concluded that Harken had overstated its profit that year - in part because the company had extended a loan to the buyer of its subsidiary.

Bush was asked if Harken's method of accounting for that sale was similar to some of the ways that Enron manipulated its profits. He flatly rejected that comparison, saying Harken intended no deception.

"In the corporate world," the president said, "sometimes things aren't exactly black and white when it comes to accounting procedures."

Sun staff writer Julie Hirschfeld Davis contributed to this article.