The revelation of former President Joe Biden ‘s cancer diagnosis has seemed to halt the ongoing debate over his fitness for office. But the co-author of the new book “ Original Sin ” tells Variety that conversation is fair, and should continue.

Sen. Ron Johnson is launching an investigation into former President Biden's health, he told Axios. Why it matters: The news of Biden's cancer diagnosis as well as new revelations about the White House's efforts to hide the former president's deteriorating health has reignited attacks from the GOP about Biden's fitness to carry out the duties of commander in chief.