Providence - Supporters of a closed Republican primary in Rhode Island argue it would give GOP loyalists the ultimate say in choosing a nominee, while opponents contend that the proposal would violate state law.

The executive committee of the state Republican Party on Tuesday will discuss a plan to close their primary so only registered Republicans can vote in it.

The proposal is intended to bar unaffiliated voters - who outnumber Republicans and Democrats and who can opt into either party on primary day to cast a ballot - from unduly influencing the outcome of the GOP primary.

"I believe that we should have Republicans affecting the Republican primary and not Democrats crossing over to control it," said Michael Napolitano, the Republican chairman for the town of Lincoln. He is not an executive committee member but strongly supports a closed primary.

The party's executive committee is expected to take up the issue Tuesday in Warwick. It will decide whether the closed primary proposal should be forwarded to the state's party members. A similar proposal was discussed months ago at a sparsely attended committee meeting and did not advance.

A spokesman for Secretary of State A. Ralph Mollis said a closed primary appears to violate state law, which the office interprets as permitting unaffiliated voters to vote in primaries even if a party changes its internal rules to bar them.

But Republicans say the U.S. Constitution and federal case law establish that parties have autonomy over their own primaries. They expect to survive any court fight.

It's unclear whether a closed primary could be organized in time for the 2010 election. Party Chairman Giovanni Cicione said it would be more practical to implement it in 2012, but other Republicans say the change should happen now.

"We do not need any distractions during the election cycle," said executive committee member Raymond McKay, president of the Rhode Island Republican Assembly. "That's why this needs to happen quickly."

Democrats outnumber Republicans nearly 4-to-1 in Rhode Island, with about 287,500 registered Democrats compared with 72,800 registered Republicans, according to the Secretary of State's office. There are roughly 335,300 unaffiliated voters.

The Republicans' only declared candidate for governor, Rory Smith, dropped out of the race last month. Some Republicans are hoping former Cranston Mayor Stephen Laffey will run, and John Robitaille, the communications director for Gov. Don Carcieri, has said he's interested in a bid.