Breaking via NYT: Trump told John Bolton in August about quid pro quo [View all]
Bolton's motivations for testimony - he has a story he wants to tell, and he is concerned he'll be accused of holding stuff back to juice his book sales instead of speaking out

"The president's statement as described by Mr. Bolton could undercut a key element of his impeachment defense: that the holdup in aid was separate from Mr. Trump's requests that Ukraine announce investigations into his perceived enemies."
Breaking via NYT: Trump told John Bolton in August that he wanted to continue freezing security assistance to Ukraine until officials there helped with investigations into Democrats including the Bidens, according to an unpublished manuscript by Bolton.
https://www.nytimes.com/2020/01/26/us/politics/trump-bolton-book-ukraine.html?smid=nytcore-ios-share
MORE:
https://www.baltimoresun.com/news/nation-world/ct-nw-nyt-trump-john-bolton-book-ukraine-20200127-tpyagzhew5ck3jn7lzmbr7hwpy-story.html
https://www.dailykos.com/stories/2020/1/26/1914304/-House-impeachment-managers-Bolton-directly-contradicts-the-heart-of-Trump-s-defense?utm_campaign=recent