Washington: US President Donald Trump and the Republican Party are suing California over recent legislation requiring presidential candidates to file tax returns in order to stand in primaries. State Governor Gavin Newsom, a Democrat, signed the law last week. In two lawsuits, the plaintiffs said it was unconstitutional as it added an extra requirement to run for president, the BBC reported on Tuesday. Trump has refused to release his tax returns, saying that they are under audit. (IANS)