JUDY WOODRUFF: There's a split tonight between Donald Trump and his own Republican Party, at issue, serious allegations that the Russians were playing spy games during the presidential campaign.
John Yang begins our coverage.
JOHN YANG: Top congressional Republicans put themselves at odds with President-elect Trump today, calling for investigations into possible Russian attempts to influence the election.
SEN. MITCH MCCONNELL, Majority Leader: Obviously, any foreign breach of cybersecurity measures are disturbing, and I strongly condemn any such efforts.
Well, let me just speak for myself. The Russians are not our friends.
DONALD TRUMP (R), President-Elect: I think it's just another excuse.
JOHN YANG: On Sunday, Mr. Trump dismissed the CIA's conclusion that the Russians were trying to help him win as ridiculous. He pointed to apparent disagreements between the spy agency and the FBI.
DONALD TRUMP: I have great respect for them. But if you read the stories, the various stories, they're disputing. And certain groups don't necessarily agree. Personally, it could be Russia. It — I don't really think it is. But who knows? I don't know either. They don't know and I don't know.
JOHN YANG: This morning, he tweeted that: "If the election results were the opposite and we tried to play the Russia/CIA card, it would be called conspiracy theory."
Russia is also an issue with a potential secretary of state in the Trump administration, ExxonMobil CEO Rex Tillerson. He's done a lot of business there and has close ties to President Vladimir Putin. That's a reason for concern, say some Senate Republicans, including John McCain.
SEN. JOHN MCCAIN (R-Ariz.): Maybe those ties are strictly commercial and got to do with his business in the oil business. Fine. But we will give him a fair hearing. But is it a matter of concern? Certainly, it should be a matter of concern.