Historically, Prof. Russell said, judges sometimes take an unexpected turn toward liberalism or conservatism once they settle onto the bench. "The acid test for Harper will be: Is there any chance of the nominee becoming an activist?" he said. "I think they will be looking for neutered judges."
York University law professor Bruce Ryder said that a cautious court can have as much impact as a bold, interventionist one. He called the phenomenon, conservative judicial activism: "Narrowly construing Charter and other limits on government power, even if it means rolling back protections provided by past precedents."
Appointed to head the court in 2000, Chief Justice McLachlin has been a leader for her times. An able jurist who lived through a period of factionalism on the court in the 1990s, she emerged with an inclination toward consensus.
"That court was really under a microscope," said Osgoode Hall law professor Jamie Cameron. "I would say that one of the objectives she set for herself as chief justice was to settle things down. She is still willing to take risks, but on a highly, highly selective basis."
"She is a very good judicial strategist," Prof. MacKay agreed. "Her effectiveness may explain the very high degree of support the court has. She chooses her cases. She defends the Constitution, but not in every case."
Chief Justice McLachlin also has a tough streak. Some legal observers believe that her desire to see the court speak unanimously has led to judges diluting principles or positions in order to minimize the dissenting or concurring reasons that are released.
To take two recent examples, legal academics loudly denounced the court for taking the easy way out in cases involving the Charter rights of terrorist suspect Omar Khadr - where it found that his rights had been violated but offered little in the way of a remedy - as well as the scope of access to information laws.
Prof. Cameron said that she pines for the days when strong individualists engaged in intellectual combat on the court.
"Although it can be confusing when several members of the court write, it is an important aspect of the intellectual process and the ferment that is necessary for the law to develop," she said. "For the most part, this has been a quiet and unassuming court. It is focused on minimalist decision making and keeping a low profile for the court. They are managing their docket in a keep-the-spotlight-away-from-me kind of way."
In recent years, there has been a decline in the number of successful Charter of Rights claims. Even when the court finds in favour of a Charter claimant, it tends to craft a careful compromise that respects the aims of parliamentarians. "The evolution of Charter rights has slowed right down," Prof. Cameron said. "And when it's slow at the top, lower courts are not going to be as likely to take chances."
The number of appeals the court decides has also fallen from an average of 90-100 to approximately 60-70 per year. It has also slashed the number of cases that are granted leave to appeal by 30-40 per cent. And many lawyers question whether the Court is dodging some of the tougher, but more significant, cases.
"I hear surprise from seasoned veterans across Canada on this point," said Henry Brown, a lawyer with Gowlings LLP who specializes in Supreme Court work. Mr. Brown, said that the court is no longer as diligent about hearing cases where appellate courts have reached differing conclusions.
"Conflicting judgments of the appeal courts are simply intolerable in Canada because they result in Canadians being treated differently depending on the province they live in," he said. "Canadians will suffer as a result."
However, Prof. MacKay said that the power of the Charter to influence policy continues even in periods of restraint. "The indirect role of even threatening litigation provides significant negotiating power," he said. "Media play is an important role. When an issue is interesting or important enough, even lower-court decisions get a lot of coverage."
Some court watchers believe that Chief Justice McLachlin may choose to retire after setting a record next year for being the longest serving jurist in that role. Besides filling her vacancy, Mr. Harper would then find himself choosing her successor as chief justice.
"For the most part, we have convinced ourselves that our judges are not chosen for partisan reasons, and I think that's right," Prof. Cameron said. "But I certainly don't rule it out as the way of the future. This is a Prime Minister who has an agenda, and he has not been able to implement his agenda until now. We can look forward to a court that is even more conservative and deferential."