As President Trump keeps talking, he makes it more and more difficult for his supporters to mount an actual defense of his underlying behavior.

Trump's pushback against impeachment efforts seemed to be gaining some traction on Wednesday with the revelation that House Intelligence Committee Chairman Adam Schiff lied about having had contacts with the Ukraine whistleblower. In fact, the whistleblower reached out to his office before filing the complaint. This came on the heels of Schiff improvising a version of Trump's call with Ukrainian President Volodymyr Zelensky during a congressional hearing rather than just reading directly from the text of the call. In a highly politicized impeachment fight, being able to portray a leader of the opposition as being dishonest is a way of undermining public confidence in the integrity of the impeachment process.

But Trump cannot help himself from making statements that keep his own conduct front and center. On Thursday morning, Trump stood in front of the White House and not only said that Ukraine should investigate the Bidens but also China.

"China should start an investigation into the Bidens because what happened in China is just about as bad as what happened in Ukraine," Trump said. "So I would say that President Zelensky, if it were me, I would recommend that they start an investigation into the Bidens because nobody has any doubt that they weren't crooked. That was a crooked deal 100%."

Trump's defenders want to focus on Schiff and the media and the deep state because it's really difficult to argue that Trump's underlying conduct has been a positive thing. He sees no problem with asking foreign countries to investigate a domestic political rival, even if, in the case of China, it's an adversary.

His comments were not about assistance with an ongoing Department of Justice inquiry into the origins of the Russia investigation or about the national interest in fighting corruption in Ukraine. Clearly and explicitly, he's stating that he wants foreign governments to investigate a political rival.

Whether or not this rises to the level of removing him from office without a more explicit threat or quid quo pro is a different question from whether objectively, Trump's behavior here is defensible.

Evaluating Trump here does not depend on trusting whistleblowers or deep state leaks or anonymously sourced media reports or dishonest Democrats. Everyone can see and hear what Trump said on video. If people want to defend anything, they should defend that.

Trump's defenders can point fingers at the coordinated efforts of leftist institutions to take down Trump all they want. But just because people are out to get him doesn't mean he didn't do anything wrong.