The Supreme Court of Canada is about to transform, as half its membership gets set to retire. But few Canadians seem interested, says the author of a new book, even though the Court could well be one of the strongest influences on our everyday lives.

Because of mandatory retirement at age 75, four of the Supreme Court's nine justices will be retiring within the next four years; others may choose to step down as well.

This gives Prime Minister Stephen Harper the chance to "stamp his own image on the Court" with his picks for replacements -- on top of the two justices he's already appointed, says Philip Slayton, a former law professor and author of "Mighty Judgment: How the Supreme Court of Canada Runs Your Life."

Among the court's current justices, most were appointed in the early 2000s. Two were appointed by former PM Paul Martin and four by former PM Jean Chretien. Chief Justice Beverly McLachlin, who has been on the bench the longest, was appointed in 1989 for former PM Brian Mulroney.

Since court appointees are typically in their mid-50s, the justices that Harper selects could sit on the bench for 20 years or more, Slayton points out.

"So, long after Prime Minister Harper has gone off to do something else, the judges he's appointed will be sitting there in Ottawa deciding fundamental questions of social and political principle," Slayton said in an interview with CTV.ca.

So why aren't Canadians taking notice and asking to have more of a voice in the selections, he wonders.

"This seems to be one of those issues that doesn't grab the public's imagination and I'm not sure why that is, because it certainly grabs attention in the United States," Slayton says.

In the U.S., Supreme Court appointments are highly politicized since the court itself can be highly partisan, issuing split judgments based on the judges' political leanings. Here, in Canada, we prefer to believe that our Supreme Court is less political. But Slayton says that doesn't mean Harper won't make appointments based on his own political beliefs.

"I would say to you that Prime Minister Harper is the most ideological prime minister we've seen in a long time. He has a pretty firm, well-defined set of conservative beliefs. For example, he definitely favours the prerogatives of the police over the rights of the criminally accused. So you can expect he'll appoint judges who favour the police over the accused," Slayton predicts.

The Supreme Court's influence reaches well beyond police rights, of course. In recent decades, the court has decided such issues as the right to abortion, gay marriage, and the right of Quebec to secede from Canada. At the moment, they're deciding whether the country's prostitution laws need an overhaul.

Slayton argues in "Mighty Judgment" that the Supreme Court of Canada may have become a larger influence on the lives of Canadians than the politicians we've elected.

"What's happened since 1982, when the Charter of Rights and Freedoms became part of our Constitution is that a lot of the questions that were once political questions and were decided in the political arena by people we elected and that we could un-elect if we felt so inclined -- these questions have been re-characterized as legal questions decided by judges whom we didn't elect and whom we can't kick out if we don't like what they do," he says.

In part, the politicians have themselves to blame, since they're often the ones referring matters to the court. Recently, they asked the court to decide whether plans for a national securities regulator are unconstitutional -- an issue that has pitted the provinces against one another.

"It's a political hot potato. But if it's a political hot potato, what's it doing sitting before the Supreme Court of Canada? Why aren't the politicians sorting it out?" Slayton says.

And why aren't Canadians demanding more oversight of the appointment process that selects the justices who make these decisions, Slayton wonders.

In the U.S., the president can nominate new Supreme Court justices but must then leave it to the Senate to vet and confirm those nominees. In our system, the prime minster simply makes an appointment in a non-public process, says Slayton, so that Canadians often don't learn the justice's name until they read about it in the news. (And even then, how many Canadians can think of the names of all or any of our Supreme Court justices?)

Harper has promised in the past to reform the court appointment process to make it more open to the public. He began some of those reforms with the selection of Justice Marshall Rothstein in 2006, when an ad hoc committee interviewed Rothstein before his selection "in a softball sort of way," says Slayton. Then the process was pushed aside for the appointment of Thomas Cormwell.

Still, it was a start, and one that Slayton hopes Harper will return to for future picks.

"What I'd like to see is the process to become more transparent and involve Parliament. And there are some signs that Harper would like that, although he'll certainly never relinquish his ultimate power of the process," says Slayton.

Slayton also argues for non-renewable terms for the court's justices in "Mighty Judgment," say, terms of 12 to 15 years like they have in South Africa.

"This idea might get some traction because it looks to me not dissimilar from what Prime Minister Harper has been in favour of with the Senate. He wants eight-year terms for senators," says Slayton. "And the arguments he gives in favour of that look to me like they'd be readily transferrable to the Supreme Court."