AP Photo/Matt RourkeRepublican presidential candidate Donald Trump has a problem with the forthcoming presidential debate schedule, in which he will face his Democratic rival, Hillary Clinton, one-on-one. In a series of tweets that began Friday, Trump appeared to accuse Clinton and the Democratic Party of trying to "rig" the general-election debates by scheduling them next to prime-time NFL games happening in the fall. The Republican National Committee's chief strategist Sean Spicer echoed Trump's grievances in a CNN interview Saturday, saying "The entire system needs to be relooked at." The presidential debates are organized by the Commission on Presidential Debates, a nonpartisan group that announced the general-election debates dates nearly one year in advance, and long before Trump won his party's nomination. Trump doubled down on the accusations Saturday in an ABC News interview with George Stephanopoulos: "I got a letter from the NFL saying 'This is ridiculous.