The whistle-blower complaint at the heart of the Ukraine scandal alleges that the U.S. ambassador to Ukraine, Marie Yovanovitch, was fired because Rudy Giuliani and his allies had attacked her as hostile to President Trump and his goal of ginning up an investigation of Joe Biden. But the report had to connect some dots. It had no direct evidence that Trump had fired her over the Biden investigation.

Now there is evidence. It comes from, of all people, Giuliani himself. In an interview with The Wall Street Journal, the Trump lawyer admits that -- the language is the Journal's characterization -- "in the lead-up to Ms. Yovanovitch's removal, he reminded the president of complaints percolating among Trump supporters that she had displayed an anti-Trump bias in private conversations. In Mr. Giuliani's view, she also had been an obstacle to efforts to push Ukraine to investigate Mr. Biden and his son Hunter."

So Giuliani's account heavily suggests that Trump decided to fire Yovanovitch because she was standing in the way of their plan to pressure Ukraine to go after Biden.