State Sen. David Johnson, one of the senior members of the Iowa Senate, says he has suspended his Republican Party membership to protest "the racist remarks and judicial jihad" by presumptive GOP presidential nominee Donald Trump. Johnson, 65, a resident of Ocheyedan in northwest Iowa who has served 18 years in the Iowa Legislature, said he changed his voter registration on Tuesday from Republican to "no party." He told The Des Moines Register he has not decided yet whether he will quit the Republican Caucus in the Iowa Senate. "I will not stand silent if the party of Lincoln and the end of slavery buckles under the racial bias of a bigot," Johnson said, referring to Trump. His criticism was prompted by Trump's comments that federal Judge Gonzalo P. Curiel, who is presiding over a lawsuit involving the now-closed Trump University, was biased because of his Mexican heritage. The judge was born in the United States. "Mark me down as Never Trump," Johnson said. But Johnson also said he will never support Hillary Clinton, the likely Democratic Party nominee for president.