Senate Republicans say Hunter Biden, former Vice President Joe Biden’s son, is the first person they think the President Trump’s defense team should call as a witness if they get a chance in the upcoming impeachment trial of Trump.

Seven House managers named by House Speaker Nancy Pelosi on Wednesday will present their case in the Senate trial, set to start Jan. 21. It’s an open question whether they’ll get to call witnesses to bolster their case for two impeachment counts against Trump in the Ukraine military aid affair.