Sen. Ron Johnson wants to confirm and investigate the origins of the report by the alleged whistleblower that triggered the impeachment trial against President Trump.

Johnson, a Wisconsin Republican, predicted on Monday that the acquittal of Trump in the Senate would be soon. Johnson, chairman of the Senate Homeland Security and Governmental Affairs Committee, said lawmakers should then turn their attention to the whistleblower, whose complaint about Trump's interactions with Ukraine President Volodymyr Zelensky kicked off the impeachment process.

"At some point in time, I'd kind of like to know how this all got generated," Johnson told the Washington Examiner. "I mean, what was behind all of this? I think there's an awful lot of suspicious activity."

Johnson sent a letter to the National Archives in November demanding information about numerous meetings National Security Council personnel had during the Obama administration with Ukrainian officials and Democratic National Committee official Alexandra Chalupa at the White House.