Despite efforts by Lugar to win more concessions from Bill Clinton on guarding against ethics conflicts, his wife insisted disclosure rules already in place were carefully crafted and adequate to avoid any conflict.

"It is not unique, however, for spouses of government officials to work, and there are very well established rules for what is expected when that occurs," she said.

Lugar was not convinced, though he assured Clinton of his vote.

"I plead for you, really, to give even more consideration," Lugar gingerly suggested.

Lugar said he worries that foreign governments or others might try to curry favor with the secretary of state by donating money to the good works group run by her husband. Lugar said the possibility for apparent conflicts of interest are obvious, even if both Clintons have only the best of intentions.

Before the hearing, Lugar made four suggestions to Clinton's staff on how to improve transparency in her husband's charitable fundraising, said the senator's spokesman, Andy Fisher.

The Obama administration would accept only one of the proposals — that the foundation provide a clear picture of its annual donations, Fisher said.

Lugar also wanted the foundation to immediately disclose donations of $50,000 or more, alert ethics officials when such sizable donations are pledged and apply the same stringent requirements to foreign businesses. The current plan only subjects foreign governments to scrutiny by State Department ethics officials and would not require a review of contributions by foreign businesses — a loophole that could easily be exploited, Lugar warned.

Vitter followed up, insisting that Bill Clinton's charity fundraising posed "real and perceived conflict issues."

After a long Clinton answer, Vitter interrupted to complain that she was eating up the time alloted for his questions.

But for the most part, Vitter's Republican counterparts did not press the attack. It was Clinton's day.

She sat at a small, black-draped desk, with a retinue of advisers behind her, her husband conspicuously absent. Obama spokesman Tommy Vietor said the former president was watching the hearing elsewhere with his wife's mother. Clinton's daughter, Chelsea, sat behind her in the audience.

"President Clinton wanted to make sure the attention was focused on Sen. Clinton," Vietor said.

The questions began with Iran, a subject on which Clinton once suggested Obama was naive.