WASHINGTON -- The Supreme Court seemed inclined yesterday to curb what might be called the "McCain factor" in politics -- allowing independents and outsiders to help select a party's candidates.
Arizona Sen. John McCain, a Republican, did well in several of this year's presidential primaries by reaching across party lines to gain the support of Democrats and independents in states allowing "crossover" voting. He did not fare as well against Texas Gov. George W. Bush in states where only Republicans could vote in the party primary.
That experience was a backdrop to yesterday's one-hour hearing before the justices in a California case that tests the constitutionality of state laws that open party primaries to nonmembers of the party.
Several justices -- perhaps enough to make a majority -- reacted negatively to a measure approved by California voters in 1996 creating what is called a "blanket primary."
Under that system, a voter receives a single ballot listing all the candidates, regardless of their political affiliation or lack of one. The voter may then hopscotch across the ballot, picking a candidate from one party for one office, a candidate from another party for a different office and so on.
Justice Sandra Day O'Connor, who emerged yesterday as a strong critic of that approach, told a lawyer for the state of California: "The very essence of the party's right is to define its own message and decide its own candidates."
She said the blanket primary appeared to be "tremendously intrusive" into the party's effort to get its preferred candidates chosen to run in the general election.
Justice Antonin Scalia denounced the California system as "democracy carried to an extreme." He said it could make it impossible for a party that "wanted to go in a different direction" from existing policies to get its favored candidates chosen in primaries.
Chief Justice William H. Rehnquist and Justice Anthony M. Kennedy also were openly skeptical about the impact on parties' policy messages, and Justice Stephen G. Breyer expressed concern that the measure could have a heavy impact on minor or splinter parties that count on their candidates to convey their ideological views.
Three other states -- Alaska, Louisiana and Washington -- have blanket primaries. Twenty-one others have "open primaries," and it appeared that the constitutionality of that form of balloting also could be affected by the outcome of the California case.
In an open primary, a voter must choose a party ballot on election day. The voter is then confined to voting for the candidates on that ballot. The primary is said to be "open" because the voter need not be a member of the party whose ballot he chooses. Other states use a closed primary, in which the voters get ballots only for the party in which they are registered.
In Maryland this year, Democrats held a closed primary. Independents were permitted to vote in the Republican contest.
Thomas F. Gede, an assistant attorney general for California, strongly defended opening up primaries to all voters, saying that "elections belong to the people," not the parties.
California's blanket primary, Gede said, has encouraged more voters to go to the polls, has cut down on voter "alienation" toward the parties, and has reduced "excessive partisanship."
Four California parties -- Democratic, Republican, Libertarian and Peace and Freedom -- are joined in the appeal seeking to nullify the blanket primary.
Their lawyer, George Waters of Sacramento, called that kind of primary "a wholesale assault on a political party's right to choose a standard-bearer who best represents that party's ideology."
Waters argued that the court could strike down the blanket primary without endangering the open primary approach, a point Gede disputed.
Gede said that if the court opts for "party autonomy," such a ruling would not only threaten open primaries, but even election-day voter registration.
The justices' reaction to the blanket primary reflected their views only at the hearing stage of the California case. As they deliberate in private in coming weeks, their views could change. A final ruling is expected by early summer.
Before the hearing, the court issued a number of orders in new cases. In one of those orders, the court cleared the way for South Carolina to end video gambling in the state -- a $2.8 billion-a-year industry -- on July 2. Justices refused to hear an appeal by Joytime Distributors & Amusement Co. of Greenville, owner of 164 video gambling machines.
The Associated Press contributed to this article.