Self-assured, and remarkably relaxed for a man in the eye of so vicious a storm, the 61-year-old obstetrics and gynaecology professor from Tennessee insisted to the Senate Labour and Human Resources Committee that its debate was "not about abortion, nor about my credibility. It is about my qualifications and credentials to serve as Surgeon-General."
By common consent those credentials are excellent. Unfortunately and inevitably, however, during an eminent career spanning almost four decades and the delivery of tens of thousands of babies, Mr Foster has also performed some abortions. They were, he explained yesterday, to preserve the health of patients.
And in a country almost as obsessed with statistical precision as it is divided on the issue of abortion itself, he has committed the scarcely lesser sin of getting confused over the figures. Immediately after his nomination in February, he spoke of "one or two" abortions, before adjusting that to "several," and finally to a documented count of 39. "I shouldn't have guessed," Dr Foster conceded yesterday, "That was a mistake, but an honest mistake. I have never tried to deceive."
Yesterday signs were growing that a majority of nine Republicans and seven Democrats on the Committee would vote to send the nomination to a final vote on the Senate floor. The Democrats are solidly behind him, while two or three Republicans, including the Committee's chairwoman Nancy Kassebaum of Kansas, seemed to be leaning his way.
Dr Foster had been reduced to a "cardboard caricature" and a "pawn in our abortion debate," Ms Kassebaum, herself a supporter of abortion rights, said in her opening statement, while the liberal Vermont Republican James Jeffords has indicated he will support Dr Foster.
In the trickiest position of all, however, was Bill Frist, who before his election to the Senate was a prominent Nashville surgeon and close professional colleague of Dr Foster. If Mr Frist's praise yesterday for the nominee's "outstanding work as a physician" is any criterion, he would be personally delighted to see his old colleague installed as Surgeon- General.
The requirements of Republican politics, however, dictate otherwise. As Mr Frist admits with some understatement, the Republican leadership "has made it clear" it does not want Dr Foster to be confirmed. The reason is simple. Most Americans favour legal abortion - but not the committed Republicans who vote in next year's presidential primaries, in which four Republican Senators will be competing, led by the current front-runner and Ms Kassebaum's colleague from Kansas, the Majority leader Bob Dole.
Faced with the risk of an embarrassing party split, between a small group of moderates and the majority who oppose the nomination, Mr Dole is threatening simply not to bring the Foster confirmation to the Senate floor. Should he be forced to do so, Senator Phil Gramm of Texas has warned he will mount a filibuster to prevent it coming to a vote.
Whatever happens the real winner may be President Clinton. If Dr Foster wins against the odds, the White House can claim a singular victory. And if he goes down in flames, he will at the very least have exposed those divisions between conservatives and moderates which the Republicans have been trying to put behind them since President Bush's defeat in 1992.