Former national security advisor John Bolton's new book "The Room Where It Happened" asserts that President Donald Trump should have been investigated for possible impeachment beyond just campaign in Ukraine, including an allegation that Trump begged China's president to help him win re-election by buying American crops.

Bolton did not testify during Trump's impeachment hearings last year, and his offer to testify in the Senate trial was blocked.

NBC News Political Director Chuck Todd told Boston Public Radio on Thursday the allegations are "shocking" but not surprising, and come at a politically relevant time as the 2020 election nears.

Trump has long claimed to be tough on China, but Bolton's allegations undercut that narrative, potentially giving presumtive Democratic nominee Joe Biden fodder to work with, said Todd.

"I think the China stuff is the most damning politically simply because Trump campaign wants to make Biden weak on China, wants to create the idea that Biden's soft on China," he said. "Well John Bolton is now a character wtiness on behalf of Joe Biden."