President Bush nominated federal appeals court Judge John Roberts Tuesday evening to fill the seat on the Supreme Court vacated by retiring Justice Sandra Day O'Connor.

While both sides of the aisle have acknowledged that Roberts is a well respected jurist with impeccable credentials, both Republicans and Democrats, liberals and conservatives, have indicated that the confirmation process will include close scrutiny of Roberts' personal views on key controversial issues, like abortion.

For some insight into what Americans can expect from Roberts' confirmation process and what the lifetime appointment of the 50-year-old Roberts would mean for the court and the country, FOX News spoke with Prof. Robert Zelnick, author of "Swing Dance: Justice O'Connor and the Michigan Muddle" (Hoover Institution Press, 2004). Zelnick is a Hoover Institution research fellow and chairman of the Department of Journalism at Boston University.

Given Judge Roberts' thin “paper trail” of rulings and opinions, how do you see his confirmation process playing out?

I think that unless some personal item crops up, he’ll be confirmed. He will not be rejected on ideological grounds…The filibuster will not be a viable anti-candidate strategy. Liberal colleagues from his days at Harvard and Washington will come forward to tout his credentials and describe his philosophy as mainstream, even if it is toward the right of the mainstream.

Despite this lack of opposition material, are there rulings and opinions of his that could be a particular obstacle in his confirmation?

The brief he filed on Roe v. Wade was part of his responsibility as deputy solicitor general for the Justice Department. In his Circuit Court confirmation hearings he referred to Roe v. Wade as well-settled law which, given his personal views, he could enforce. Now, clearly he will have different powers as a Supreme Court judge than he did as an appellate court judge where his job was to uphold Supreme Court rulings, but the abortion issue is not going to beat him.

It says something about the paucity of opposition material when people are talking about a Wilderness Act case and his ruling that the frog in question was entitled to no federal protection since he and his clan resided exclusively in California. Bottom line: He’s not going to be beat by his ruling on a frog.

What do you foresee as the biggest issues that may come before the Supreme Court within the next few years?

Well, the Patriot Act will come up, as well as various detention practices against alleged terrorists. There will be more commerce clause cases--whether it can continue to be rolled back as a source of federal regulatory power. There will be important business litigation regarding the conduct of and damage awards in class action law suits. The question of the full faith and credit clause in relation to same-sex marriages may well come up as some states sanction these arrangements. There will likely be important rulings on challenges to the death penalty.

Abortion will likely come up down the road again, as all important issues eventually do, perhaps beginning with a test of partial-birth abortion proscriptions.. But at this point in time, it would take two votes to overturn Roe v. Wade.

But what about the partial-birth abortion ban that is working its way to the high court?

I don’t know if that’s a fair test of Roe v. Wade. I personally know supporters of Roe v. Wade who are also supporters of the partial-birth ban. But a case that reaches the Supreme Court would be the first hard indication of the Roberts view of the subject.

What major Supreme Court rulings do you see as being the most vulnerable to being weakened or altered by this court?

The area that could be the most vulnerable to reversal is affirmative action. O’Connor was the swing vote. If that came up and the new Justice Roberts took an opposition position to the justice he replaced, he would change the law. In the University of Michigan case, for example, one more vote against the Law School procedure would have banned race preferences in state university admissions.

Is it possible right now to compare Judge Roberts to O’Connor, in terms of being the “swing vote?”

I think he will be a swing vote, it’s just a matter of which way he’ll swing. The Court right now (without O’Connor) is 4-4 on many critical questions.

What impact will he have on the Court’s ideological composition. Will he tilt it more to the right or left?

I think he will turn out to be a conservative in many areas but one who will be respectful of stare decisis (previous Court rulings). My sense is that he will be more of a traditional kind of conservative, not a passionate firebrand like (Clarence) Thomas. Nor, in my totally intuitive feeling, will he embrace the so-called “original intent” approach to constitutional interpretation--epitomized by the likes of Robert Bork and Justice Scalia—which requires adherence to the interpretation of those who wrote and adopted the Constitution, leaving it for the Amendment process to work changes in this basic law.

He will, I believe, have great respect for stare decisis as O’Connor was, but I don’t look for the sort of self-restraint practiced by justices like Holmes, Jackson and Frankfurter, a type of judicial conservatism not held in favor by many of today’s conservative activists. Roberts may not be the social conservative that some on the Christian right may have been hoping for.

Prof. Robert Zelnick is the author of "Swing Dance: Justice O'Connor and the Michigan Muddle" (Hoover Institution Press, 2004), which examines Justice Sandra Day O'Connor's key role in the controversial University of Michigan affirmative action cases of 2003. He is the chairman of the Department of Journalism at Boston University and a Hoover Institution research fellow whose expertise includes U.S. politics, affirmative action, race preferences, media issues and military-media relations. Prof. Zelnick is an Emmy Award-winning journalist who, during a 20-year career with ABC News, covered political and congressional affairs for ABC Morning News, World News Tonight Saturday/Sunday and This Week.