July 3 (Bloomberg) -- President George W. Bush's two U.S. Supreme Court appointees proved as conservative as advertised in their first term, even if they fell short of controlling the outcome in some of the court's highest-profile cases.

Chief Justice John Roberts and Justice Samuel Alito voted during the just-ended term to narrow the Clean Water Act, restrict campaign-finance regulation and limit the rights of criminal suspects. They consistently allied themselves with the votes, if not always the reasoning, of Justices Antonin Scalia and Clarence Thomas.

The new dynamic placed Justice Anthony Kennedy in what may become a familiar role, as he wrote the pivotal opinions in fights over the environment, military tribunals and congressional redistricting. In each case, Kennedy either tempered a conservative victory or provided a fifth vote for the court's more liberal bloc.

``The proponents of Roberts and Alito are getting what they expected,'' said Robert Nagel, a law professor at the University of Colorado in Boulder. ``But I don't know if they expected that the opinions of those people would be in dissent.''

The Scalia-Thomas wing can point to victories in criminal law. Scalia wrote the 5-4 decision limiting the exclusionary rule, which sometimes bars prosecutors from using evidence found during an illegal search by police.

Two other 5-4 decisions, in cases from California and Kansas, gave states more leeway in setting rules for juries considering the death sentence for convicted murderers. In each of those disputes, Kennedy joined the majority, putting Justices John Paul Stevens, David Souter, Ruth Bader Ginsburg and Stephen Breyer in dissent.

Search Restrictions

Criminal defendants won one fight, a 5-3 ruling that said police officers lacking a warrant can't search a home when one occupant consents and the other objects. Alito didn't take part in that case because he had just joined the court.

``You can point to things that are not terribly discouraging,'' said the winning lawyer in the home-search case, Tom Goldstein, a Supreme Court specialist at Akin Gump Strauss Hauer & Feld in Washington. ``But on the big picture, everybody really has to be aware that the court has become considerably more conservative.''

Kennedy tipped the balance on each of those criminal-law rulings and overall was in the majority on nine of the 12 votes that split the court 5-4, according to statistics compiled by Akin Gump. That's the highest percentage of any justice.

On several occasions, Kennedy wrote his own opinion to qualify a majority's reasoning. In the exclusionary-rule case, he wrote separately to say that the doctrine's ``continued operation'' is ``not in doubt.''

Kennedy in the Middle

The Clean Water Act case split the justices into three camps -- four voting for federal regulators, four siding with property owners and Kennedy taking a middle position. His opinion created a new test, saying the Army Corps of Engineers can regulate only wetlands with a ``significant nexus'' to a major waterway.

And in the term's climactic decision, barring Bush's plan to use military tribunals to try suspected al-Qaeda members, Kennedy joined most, though not all, of Stevens's lead opinion for the court. Alito dissented and Roberts, who sided with the Bush administration as an appellate judge, didn't take part.

``We clearly now have the Anthony Kennedy court,'' said Erwin Chemerinsky, a law professor at Duke University in Durham, North Carolina. ``Kennedy is very self-consciously now the swing justice.''

That role previously was held by Justice Sandra Day O'Connor, 76, who retired mid-term after Alito was confirmed as her replacement Jan. 31. Roberts succeeded the late Chief Justice William Rehnquist just before the term began in October.

Youngest Members

Roberts, 51, and Alito, 56, are the court's youngest justices. Stevens is 86, Ginsburg is 73, Scalia is 70, Kennedy is 69, Breyer is 67, Souter is 66 and Thomas is 58.

When he nominated Alito and Roberts, Bush hailed both as jurists who would strictly interpret the Constitution and not legislate from the bench. Bush earlier singled out Scalia and Thomas as two justices he especially admired.

In one of the term's first divided rulings, Roberts dissented with Scalia and Thomas in January when the court backed an Oregon law authorizing doctor-assisted suicide. The majority said the Bush administration overstepped its authority in trying to block the state law.

After Alito joined the court, he and Roberts found themselves in full agreement 89 percent of the time, more than any other pair of justices, according to Akin Gump.

Although they frequently joined Scalia and Thomas, the two new justices didn't always adopt the sweeping constitutional theories of their veteran colleagues.

Campaign-Finance Split

In the campaign-finance case, Scalia and Thomas said they would overturn a landmark 1976 Supreme Court decision that allowed some limits on contributions to candidates. Roberts and Alito opted not to sign Thomas's opinion, instead joining Breyer in voting to strike down Vermont's contribution caps as too low, without ruling out limits altogether.

``They may move there some day, but at this point, they joined with Justice Breyer, who actually wrote the controlling opinion,'' said Paul Smith, a Washington appellate lawyer with Jenner & Block.

Likewise, in a showdown over a Republican congressional redistricting plan in Texas, Alito and Roberts chose not to join Scalia and Thomas in saying that courts should never consider whether district lines are excessively partisan. Roberts and Alito said the court didn't need to reach that issue. The four joined Kennedy in voting to allow the Republican-drawn map.

Roberts and Alito dissented from a separate aspect of the ruling that said part of the Texas map illegally diluted Hispanic voting strength.

Unanimous Decisions

A flurry of divisive cases in June -- including the campaign finance, redistricting and military tribunal disputes -- enlivened a term that until then featured a string of unanimous decisions.

Even an abortion case was unanimous, as the court decided relatively narrow issues and deferred consideration of tougher questions. The court disposed of 45 of 82 cases without dissent, considerably more than in past years, according to Akin Gump.

That much unanimity may not be possible in the 2006-07 term, which starts in October. Already, the court has scheduled fights on abortion, school affirmative action, punitive damages and global warming.

``It may be a calm before the storm,'' said Nina Pillard, a law professor at Georgetown University in Washington.

To contact the reporter on this story: Greg Stohr in Washington at gstohr@bloomberg.net

Last Updated: July 3, 2006 00:09 EDT