Trump totally changed his tune on Russian hacking today. Why?

That's according to Secretary of State Rex Tillerson, who was in the meeting. "They had a very robust and lengthy exchange on the subject," he told reporters afterward. "The president pressed President Putin on more than one occasion regarding Russian involvement. President Putin denied such involvement as I think he has in the past."
Bringing up Russia's role in the election is an interesting strategy by Trump -- particularly given that White House officials had signaled in the run-up to Friday's meeting with Putin that the president might not raise the issue of election interference.
It's particularly odd given that less than 36 hours before Trump, according to Tillerson, "pressed" Putin on the meddling in the 2016 election, he was decidedly skeptical about the idea that Russia was fully to blame.
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    Trump: Russia 'and others' meddled in election 03:17
    "I think it very well could be Russia but I think it could very well have been other countries," Trump said Thursday at a press conference with Polish President Andrzej Duda. "I think a lot of people interfere."
    Trump added: "I think it was Russia but I think it was probably other people and or countries. I see nothing wrong with that statement. Nobody really knows. Nobody really knows for sure."
    That's a very different tone from the one Tillerson describes Trump taking in his sitdown with Putin Friday. On Thursday in Poland, Trump refused to even commit to the idea that Russia definitely led the meddling into the 2016 election despite the fact that the CIA, FBI and Office of the Director of National Intelligence have all reached that conclusion. By Friday, Trump was pushing Putin face to face about how Russian interference was a hindrance to moving beyond past poor relations between the two countries.
    There was also considerable confusion between the two sides about how Trump handled Putin's denial of Russian involvement.
    New York Times Moscow Bureau Chief Neil MacFarquhar tweeted that Russian Foreign Minister Sergey Lavrov had said that "Trump said he accepted statements from #Putin that #Russia had not hacked election." Lavrov's take was rapidly contradicted by a senior administration official, who told CNN that Trump did not accept President Putin's claim of non-interference in the election.
    These sorts of meetings -- particularly between two major players on the world stage representing two adversarial countries -- are always ripe for some level of misunderstanding, whether purposeful or not. The Russians hear what they want to hear, and so do the Americans. That explains some of the differing reporting on who said what in the Putin-Trump meeting.
    But what mystifies me is what changed for Trump between Thursday afternoon in Poland and Friday afternoon in Germany.
    Prior to Friday, Trump has been one of the few voices within the Republican party (or the Democratic party) who has consistently voiced doubts about Russia's role trying to meddle in the American presidential election. His comments on Thursday are broadly consistent with that skepticism; yeah, Russia probably did it....but they might not have!
    Trump's tone in the one-on-one with Putin on Friday, as related by Tillerson, is a marked change from that approach. Why? Did Trump become convinced over the last 24 hours of Russia's role in the election meddling? Is Tillerson exaggerating Trump's comments to Putin? Is this part of some sort of broader strategy aimed at keeping Russia on its heels when it comes to what to expect from Trump? Or did Trump just say it because, well, it occurred to him in the moment?
    So many questions. So few answers.