Though the White House insisted Friday that it had not been in communication with the Supreme Court over the timing of a resignation letter from Chief Justice William Rehnquist (search), rumors abound that his departure is imminent.

"Chatter," as it is known in intelligence circles, started picking up on Thursday after columnist Robert Novak (search), most recently noted for his role in the leak of a CIA officer's identity, wrote in daily papers that adding to the pressure on President Bush to choose a Supreme Court nominee to replace retiring Justice Sandra Day O'Connor (search) is "word from court sources that ailing Chief Justice William Rehnquist also will announce his retirement before the week is over."

Senior advisers to Senate Majority Leader Bill Frist, Senate Minority Leader Harry Reid, as well as top aides to Sens. Arlen Specter, R-Pa., and Patrick Leahy, D-Vt. — the top senators on the Senate Judiciary Committee — told FOX News on Friday that they knew nothing of a planned retirement announcement scheduled for Friday.

The 80-year-old Rehnquist, who is battling thyroid cancer (search), left his home early on Friday, but gave no indication what his plan is.

When asked by one reporter Friday if any speculation about his resignation is true, Rehnquist said: "That's for me to know and you to find out."

Some analysts suggested that the chief justice may have been intending to quit on Friday but because of the London terror attacks on Thursday, he would decide to delay his announcement.

It's likely that if Rehnquist had planned to retire on Friday "events have played a part in terms of when he will submit a resignation," former President Clinton's chief of staff, Leon Panetta, told FOX News.

Others suggested that Rehnquist was not going to make his decision known until after Bush returned Friday from his visit to the G-8 summit in Scotland.

O'Connor announced her retirement last Friday, giving Bush at least one appointment to the high court. Nominated by President Reagan and seated in 1981, she is the first woman to serve on the high court. O'Connor had been expected to be a conservative justice, but her record has bore her out as a moderate who has voted to preserve abortion rights and other social issues while also siding with conservatives on states' rights decisions. With her varying points of view, she has earned the title of "swing voter" on the court.

Rehnquist, born in Wisconsin, was active in the Republican Party during his years as an attorney in Arizona and was highly regarded as a former assistant attorney general for President Nixon. His reputation as a fair-minded jurist as well as someone able to form coalitions earned him widespread, bipartisan admiration throughout his tenure.

"Rehnquist plays the good solid citizen. He has his positions, they're ideological, but he doesn't try to attack, he doesn't try to go full-bore on the history," said Martin Belsky, professor at the University of Tulsa College of Law and author of "The Rehnquist Court: A Retrospective."

"He basically is the straight shooter. He has very good relationships with the justices, and more importantly, has been able to use [those relationships] in an effective way to develop pluralities of four, and more often than not, majorities of five ... he is often the conciliator."

If Rehnquist retires, Bush will be left with two openings to fill simultaneously. Some court watchers say it could change his plans on who he wants to nominate.

"It certainly makes it that much more interesting. From a political point of view ... the president has some great options," Panetta said, adding that Bush could choose a hard-leaning conservative to replace Rehnquist while also choosing a more moderate conservative to take O'Connor's place.

"What is very likely is that two vacancies would work to the advantage of the White House. The White House would conveniently be able, surely, to get a very conservative nominee through and maybe have a second nominee, like [Attorney General] Alberto Gonzales, who is somewhat distrusted by conservatives as not reliable enough. It gives the White House, frankly, a little more room to bargain and trade a bit in terms of who those nominees would be," said George Washington University law professor Jonathan Turley.

But not all court-watchers agree that the president will have to fill vacancies on the court with mirror images of the justices who sat in the seat before. Turley said binding a president to that mold could cost him his role on court decisions for years to come.

"What is at stake is nothing short of a lasting legacy for this president," he continued. "If he changes the balance of the court, shifts it to the right, to produce a consistent conservative majority, he can literally change the face of the law. There are dozens of cases that are hanging by a single vote, that vote has often been Sandra Day O'Connor's. He really can have that great effect on American law, than perhaps any prior president. It is that significant."

Ultimately, the debate on whether nominees are too conservative or not conservative enough will be fought out in the Senate. Panetta suggested that Bush's only criteria for a nominee is someone who knows how to judge.

"I think the key for the president is to appoint somebody who has a great judicial reputation, someone who has a keen mind and someone who is faithful to the Constitution," he said.

Oddsmakers are also looking for clues about the future plans of Justices Ruth Bader Ginsburg (search) and John Paul Stevens (search), both of whom have been named as possible departures.

Ginsburg, 72, was seated on the court in 1993. In September 1999, she underwent surgery to treat colon cancer after which she received chemotherapy and radiation treatment from October 1999 to June 2000.

Stevens, 85, has sat on the court since 1975. Sources told FOX News that Stevens hired two law clerks from Yale University in the last two weeks, suggesting that he has no intention of stepping down.

Stevens, who was appointed by President Ford, turned out to be among the most liberal members of the court. Ginsburg, too, is a liberal-voting member of the court.

The current court has been in its formation for the last 11 years. Before that, Justice Harry A. Blackmun (search) stepped down and Clinton tapped the second justice of his presidency, Stephen G. Breyer (search).

FOX News' Major Garrett, Brian Wilson and Jane Roh contributed to this report.