OLYMPIA, Wash. — Republican leaders are bracing for a combative Washington state party convention as supporters of presidential candidate Ron Paul look to seize more delegates from presumptive nominee Mitt Romney.

Paul devotees have fared well in caucus states, recently seizing control of state conventions in Maine and Nevada. Washington’s convention at the end of this month offers yet another chance to add delegates so that the campaign can have more influence at the national convention in Florida.

Kirby Wilbur, the state GOP chairman, said Paul has strength in the 7th Congressional District anchored in Seattle and the 3rd District that stretches from Olympia to Vancouver. He expects Paul’s campaign will pick up a minimum of six to nine delegates in Washington out of 40 possible.

They could secure even more delegates if they can convince supporters of former candidate Rick Santorum to side with them, and Wilbur also expects Paul supporters to use some aggressive gamesmanship to try and pick up more.

“I’d be disappointed if there wasn’t,” Wilbur said. “I don’t want to have a boring convention.”

Still, Wilbur said he doesn’t believe Paul supporters here will be as disruptive as they have been in other states. He said the state party leadership has a good relationship with Paul backers and that he thinks the state’s convention rules are fair and straightforward.

A Paul spokesman did not return a message seeking comment.

Delegates that go to the state convention are not pledged to any candidate but were mostly chosen at local conventions based on their support for a given candidate. Wilbur estimates that a little more than half back Romney, one-quarter back Paul and another 20 percent backed Santorum.

The delegates will choose three national delegates per congressional district. Then the whole convention will chose 10 other at-large delegates.

Graden Neal, the state’s volunteer coordinator for the Santorum campaign and an alternate delegate at the state convention, said Santorum supporters seem to be split about whether to back Romney.

“There are some people that want to send a conservative message and probably would still be in a coalition with the Ron Paul camp,” Neal said.

Paul isn’t within striking range of Romney, who already had 856 delegates ahead of today’s votes in North Carolina, Indiana and West Virginia. Romney is likely to reach the 1,144 delegates he needs to clinch the nomination by around the time Washington Republicans meet for their convention. Paul, meanwhile, has only 94 delegates, according to an Associated Press count.

Paul supporters want the Texas congressman to have a speaking slot at the convention and the chance to shape the party platform to emphasize limited government.

Chris Vance, the former chairman of the state Republican Party, said he expects the state convention to be a battle. Paul’s supporters may be particularly successful because so many conservatives have been uncomfortable with Romney and because Paul’s loyalists have shown that they are willing to struggle for every last delegate.

“In a caucus convention system, they are formidable,” Vance said. “They are motivated. They will come early and stay late.”