For nearly three years, Donald Trump has ignored his own country’s intelligence community and believed that Ukraine intervened in the U.S. elections in 2016 in the hopes of undermining his candidacy. One of the underlying questions is why the Republican believes the bogus conspiracy theory.

A Washington Post report last week shed new light on the issue, explaining that Trump’s embrace of the falsehood appears to have come directly from Russian President Vladimir Putin. The Post quoted one former senior White House official who said Trump was quite explicit on this point, saying he knew Ukraine was the real culprit, U.S. intelligence be damned, because “Putin told me.”

As we’ve discussed, Trump not only believed Putin, he also acted on that belief, pressing Ukrainian President Volodymyr Zelensky to pursue, among other things, a crackpot conspiracy theory about Ukraine’s role in American election interference.

It was against this backdrop that a reporter broached the subject yesterday morning, after Trump’s Christmas video teleconference with U.S. troops deployed abroad.

Q: Sir, what did President Putin say to you that convinced you that the Ukraine interfered in the 2016 election? TRUMP: What did he say to me? Q: Yes. TRUMP: About what? Q: What did President Putin say to you when you met? TRUMP: You’re putting words in somebody’s mouth. Who are you referring to? Me? I never said anything about it. I never said a thing about it. All right, any other questions?

While it was easy to enjoy the exchange’s Abbott-and-Costello-like qualities, it was equally easy to notice this seemed like a subject Trump was reluctant to talk about.

And that’s a shame because it’s a good question in need of a good answer. The connections between Trump’s conversations with his Russian benefactor and his willingness to promote Ukraine conspiracy theories are well documented, and they reinforce concerns about the American president serving as Putin’s puppet.

Trump’s clumsy who’s-on-first routine doesn’t make those concerns go away.