McConnell's key divisions:

1. On Russia: McConnell drew a clear distinction between the Russian government's moral footing and that of the United States (a rebuke of President Trump's generous comments about Putin to Fox host Bill O'Reilly.) McConnell called Putin a "thug," said he wasn't legitimately elected, and condemned him for messing around with U.S elections.
2. On voter fraud: Asked about Trump's false claims of 3-5 million stolen votes, McConnell said there was "no evidence" that voter fraud existed in significant enough numbers to swing the presidential election. He also said he didn't want federal money spent on an investigation into voter fraud. Trump wants a "major investigation."
3. On Trump's travel ban: McConnell expressed misgivings about Trump's executive order. "Proper vetting is important to the American people," he said, "but there's a fine line here between proper vetting and interfering with the kind of travel, or suggesting some kind of religious test...we certainly don't want Muslim allies who fought with us in countries overseas to not be able to travel to the United States. We need to be careful about this."
4. On Trump attacking the "so-called" judge opposing the order: McConnell said "it's best not to single out judges for criticism. We all get disappointed from time to time at the outcome in courts on things that we care about. But I think it's best to avoid criticizing judges individually."

Why this matters: Republican House members still fear Trump, which gives the new President enormous power over the lower chamber. They're all facing re-election next year and they don't want the commander-in-chief, who has an incredible bond with many of their constituents, to target them on Twitter. But Senators are different beasts. They don't fear Trump nearly so much, and McConnell has already signaled that he'll remain his own man. Trump's biggest policy problems — the disagreement on border adjustment being a major one — will inevitably arise in the Senate.