When White House lawyers launch their defense of President Clinton today in his historic Senate trial, they face pluses and minuses.
For Mr. Clinton, one advantage is that the three-day presentation by House Republican "trial managers" appears not to have produced the groundswell of support among Democratic senators needed for conviction.
In addition, the public remains firmly in favor of keeping Clinton in office, despite what most political observers view as a well-done prosecution argument for his removal from office. As elected representatives, senators can legitimately consider the polls in their decisionmaking, Democratic senators have said.
But the process still has a way to go before a final vote on conviction or acquittal. And one important question on how the trial proceeds seems to be moving toward the prosecution's case: It appears likely that witnesses will be called to testify.
Republican prosecutors have long hoped to bring forward several key figures in the perjury and obstruction of justice case, including: former White House intern Monica Lewinsky, Clinton's secretary Betty Currie, and presidential friend Vernon Jordan. The extensive written record in the case - months' worth of depositions and grand-jury testimony - has so far not proved enough to break the president's support.
Prosecutors have hoped witnesses will either bring to light new facts or add new force to the existing story of Clinton's affair and his attempt to keep it secret.
The White House has opposed witnesses for the same reason. Witnesses will extend the length of the trial, always a risky proposition for a defendant. For Clinton, the appearance of Ms. Lewinsky will also heighten his embarrassment as he attempts to restore his dignity as president.
But now, in an ironic twist, the White House has almost been put in the position of needing the appearance of witnesses.
When the president's defense lawyers open their arguments today, they will tackle head-on the accuracy of the facts the prosecution has laid out - highlighting ambiguities and inconsistencies that can be explored only through additional testimony from key people, such as Lewinsky and Ms. Currie.
ULTIMATELY, witnesses may not hurt the president. They will reinforce the central fact that the president faces removal from office because he tried to hide an illicit sexual affair, a point a majority of the public and most Democrats, so far, believe does not rise to the level of impeachment and conviction.
If, however, fresh testimony can help the prosecution reinforce its claim that the president did lie under oath and obstruct justice, he could face serious trouble.
To date, the public hasn't paid close attention to the Senate trial. Live testimony from principal players - especially Lewinsky - could rivet public attention, a risky prospect for a president whose ultimate shield since the scandal broke a year ago has been his solid public support.
The White House defense team's expected focus on the facts represents a shift in emphasis. Until now, the main argument of Clinton's lawyers has been that the president's alleged offenses don't rise to the level of impeachment. But that argument has, to some, carried an implicit message that perhaps the president did commit crimes, just not "high crimes."
Now the White House is on notice - after the House managers' extensive presentation last week of their version of facts and their grave implications - that they can't allow any presumption that president broke the law in any way.
"If the best they can do is to say 'so what?', they may be surprised at the votes in the Senate," Sen. Phil Gramm (R) of Texas said Sunday on ABC's "This Week."
Among the factual disputes that remain are these questions: When did the president's relationship with Ms. Lewinsky begin? In what ways did he touch her, and what was the exact sequence of events that led Lewinsky to return gifts from the president?
The White House will also reportedly highlight previous testimony from Lewinsky in which she says she was never told to lie.
However effective the White House defense turns out, the math still works in Clinton's favor. If all 55 Republican senators voted to convict the president, at least 12 Democrats would have to join them to produce the two-thirds majority required for his removal.