Former Rep. Trey Gowdy (R-S.C.) explained this week how former President Barack Obama may be a relevant witness in President Donald Trump's impeachment trial.

"Part of impeachment is setting a precedent for what's going to happen in the future," Gowdy told Fox News host Sean Hannity,

"So, if the vice president can make that assertion, then he is relevant as a witness, but so too is President Obama because I would want to know whether or not he had the authority of the president at the time he made that that pronouncement that there'll be no loan guarantees unless the prosecutor is fired," he continued.

Gowdy explained that if Democrats claim that Trump has engaged in "unprecedented abuse of power" then that "makes what other presidents did relevant."

"If President Obama gave Joe Biden permission to condition loan guarantees on the firing of a prosecutor, then that makes both of them potentially relevant as witnesses," Gowdy said.

Gowdy was referring to the infamous video of Biden in 2018 bragging about threatening to withhold aid from Ukraine if the country did not fire its top prosecutor.

Biden said at the time:

I had gotten a commitment from Poroshenko and Yanukovych that they would take action against the state prosecutor and they didn't. So they were walking out of the press conference, and I said we were not going to give them the $1 billion. They said you have no authority. You are not the president. The president said ... I said call him. I'm telling you, you are not getting $1 billion. I said you're not getting $1 billion and I am going to be leaving here in six hours and if the prosecutor is not fired you are not getting the money. Well, son of a b**** ... he got fired.

Of course, Biden denies that he engaged in a quid pro quo or pushed for the firing of the prosecutor to protect his son, Hunter Biden.

However, Republicans continue to believe that Biden and his son are relevant in Trump's impeachment.