Republicans threaten boycott of debates over Clinton programs By Alina Selyukh WASHINGTON (Reuters) - Republicans are threatening to boycott 2016 presidential candidates debates sponsored by networks CNN and NBC unless the networks cancel plans for special programs on Democrat Hillary Clinton, a possible 2016 White House contender. Republican National Committee Chairman Reince Priebus wrote to executives for NBC Entertainment and CNN Worldwide, saying the planned programs were political ads for the former secretary of state and former first lady. Priebus asked the companies to scrap plans by August 14 for the NBC miniseries on Clinton and for the CNN documentary film. Representatives from Comcast-owned NBC and Time Warner-owned CNN did not immediately comment. "As an American company, you have every right to air programming of your choice," Priebus wrote in the letters to NBC Entertainment Chairman Robert Greenblatt and CNN Worldwide President Jeff Zucker. But as American citizens, certainly you recognize why many are astounded at your actions, which appear to be a major network's thinly veiled attempt at putting a thumb on the scales of the 2016 presidential election. Priebus said if CNN and NBC went ahead with the Clinton shows, he would seek a binding RNC vote that the Republican Party would not work with the two networks on its 2016 primary debates or sanction the debates sponsored by them. CNN in the past has pointed out that its film unit operates separately and without CNN's editorial guidance. NBC's Greenblatt, when asked in July about Clinton's opponents potentially demanding equal time from the network, said the series would likely air before the presidential race heats up in the spring or summer of 2015. Reporting by Alina Selyukh; Editing by Bill Trott