Fresh from being named Time magazine's Person of the Year, the 16-year-old Swede joined thousands of students in the north Italian city of Turin on Friday for a protest to pressure the government to take more action to curb carbon emissions.
"I actually wanted it to be the whistleblower this year, to be the Person of the Year", McCain said, referring to the anonymous individual who drew attention to the now-infamous July 25 phone call between President Donald Trump and Ukrainian President Volodymyr Zelensky.
Of course, our young eco-queen had no problem handling Trump's tantrum herself and responded by changing her Twitter bio to: "A teenager working on her anger management problem. Now chilling and watching a good old fashioned movie with a friend".
Hours after the president's dig at Thunberg, his campaign tweeted an edited version of her TIME cover with Trump's face on it instead.
Ms Thunberg later said she was making a literal translation from Swedish, in which the expression means to put someone on the spot with tough questions.
However, Thunberg instead appears to have focused her attention on the United Kingdom general election in a Thursday afternoon tweet where she said that "the politics needed don't exist today". "It is no secret that the President and First Lady often communicate differently - as most married couples do".
"A minor child deserves privacy", Melania Trump said in a tweet, "and should be kept out of politics". His words echo professionals in my field who dismiss me as necessarily illegitimate either because they assume that a "truly" disabled person cannot be a lawyer or capable activist, or that they can discard my work as irrelevant and meaningless specifically because I am disabled.
Michelle Obama leapt to the defence of Greta Thunberg after her husband's successor criticised a recent award to the teenage climate activist. "Like the girls I've met in Vietnam and all over the world, you have so much to offer us all", she said.
The White House has been contacted for additional comment.