Washington state Republicans are asking fellow party members to sign a pledge not to bash others in the GOP. But one candidate refuses to comply and now he can't speak at the state's political convention.

Fighting for the nomination are Rep. George R. Nethercutt Jr. (search) from Spokane and Reed Davis (search), a college professor from Seattle. Both men want to be the party's choice to challenge Democratic incumbent Sen. Patty Murray (search) in November.

The party has already thrown its backing behind Nethercutt and wants Davis to sign the pledge in order to speak at the convention later this week.

But Davis refuses to sign. He will be allowed at the convention as a delegate and he may get supporters to mount a floor challenge so that he could win the chance to speak.

The situation may sound familiar. Back in 1996 when then-presidential candidate Patrick Buchanan (search) refused to sign a similar pledge, he was not allowed to speak at the national Republican convention in San Diego.

Click here to watch a complete report by Fox News' Trace Gallagher.