When all the lawyering is done in one of the most important trials of the century, the ultimate question for the Senate will be simple: Did President Clinton's alleged conduct rise to the level of impeachable "high crimes and misdemeanors"?
Certainly, the senators standing in judgment of the president are weighing the facts in the case - whether Mr. Clinton did commit perjury and obstruct justice. But behind the strict legal arguments lies the larger issue of whether his conduct - if criminal - constitutes a "high crime" that warrants removal from office.
The meaning of the phrase "high crimes and misdemeanors" is "by far the most controversial question surrounding the impeachment process," says Alan Hirsch in his book "A Citizen's Guide to Impeachment."
In the wake of the prosecution's stinging arguments in favor of Clinton's removal, the White House defense team delivered a spirited reply this week that challenged the Republicans' facts in the case - as well as the seriousness of the alleged offenses.
The political atmosphere, crucial in any presidential impeachment proceeding, has only thickened as the senators near a vote early next week on whether to proceed with the trial and whether to call witnesses. The Rev. Pat Robertson, a leading voice among religious conservatives, has pointedly observed that the Republicans can't match Clinton's political skills - on display in his State of the Union address Tuesday night - and that the trial might as well end now.
But the House Republican team remains undaunted. When all is said and done, the question for the Senate may boil down to the meaning of two words placed in the Constitution 212 years ago: "high crimes."
The standards for impeachment, in fact, became a point of debate among the Founding Fathers at the Constitutional Convention of 1787, as White House counsel Charles Ruff argued during his testimony Tuesday. Initially, treason and bribery were the only offenses listed that would warrant impeachment. When George Mason proposed adding the term "maladministration," fellow Virginian James Madison objected on the grounds it was vague and would allow Congress to remove a president just because the members thought he wasn't doing a good job.
So maladministration was dropped in favor of "high crimes and misdemeanors," a vague phrase borrowed from English law intended to shield the president from the political whims of Congress. Mr. Ruff's point in raising this history was to show that the Founding Fathers intended to establish a high bar for the removal of the president.
But a further look at the Founding Fathers' intentions can yield a different conclusion, as the House prosecutors, or "managers," have come to. In the Federalist Papers, written to support ratification of the Constitution, Alexander Hamilton noted that an impeachable offense is one that involves "the abuse or violation of some public trust" and "relate[s] chiefly to injuries done immediately to the society itself."
Under those standards, most Republicans in the House of Representatives concluded, Clinton did commit impeachable offenses by lying under oath and obstructing justice in the independent counsel's investigation of his affair with Monica Lewinsky.
Still, some constitutional scholars say that by adding the phrase "high crimes and misdemeanors," the Founding Fathers were saying that a president can be impeached for an act that falls short of a crime, such as going on vacation during a time of war.
And the reverse, some scholars say, is also true: that a president can commit a crime that falls short of warranting his impeachment and removal from office. So, in Clinton's case, a senator can conclude that the president did commit perjury, and still vote to acquit him.
In their arguments last week, some House managers stated that because perjury is equivalent to bribery in the eyes of the law, Clinton has committed an act equal to one specifically mentioned in the Constitution as an impeachable offense.
"But the real question," says Akhil Amar, a constitutional scholar at Yale Law School in New Haven, Conn., "is whether this perjury is like bribery. That's a question on which people can disagree." He believes some kinds of perjury are as bad as bribery and some aren't. Perjury about sex in a civil case, in his view, falls short of the mark.
Another time-honored way of assessing the merits of a case is to look at the legal precedents. The challenge for the senators, then, is to decide what constitutes a legitimate precedent. House prosecutors argue that the impeachment and removal of federal judges for perjury go directly to why Clinton also should be removed. Why, the prosecutors argue, should the standard of performance for a judge be higher than it is for the president of the United States?
Clinton defenders reply that federal judges and presidents are different breeds of public servants - and that they serve under differing conditions. Presidents are elected for finite terms; judges are appointed for life. Judges also serve "during good behavior," a rule not applied to presidents.
"You can say that the different nature of the office of judge and president may mean that different standards are involved," says Buck Melton, an expert on impeachment at the University of North Carolina law school in Chapel Hill.