Former Arkansas Gov. Mike Huckabee told Breitbart News Daily on Friday that when the Senate wraps up the impeachment trial, Republicans — notably, Sen. Lindsey Graham (R-SC) — should open a separate investigation into Hunter Biden, the origin of the dossier, and the so-called “whistleblower,” whose complaint fueled the Democrats’ partisan impeachment effort.

Huckabee spoke to Breitbart News Editor-in-Chief Alex Marlow on Friday and discussed the impeachment trial in the Senate, the debate about witnesses, and what should happen once the trial concludes.

Sen. Lisa Murkowski (R-AK) is joining the majority of her colleagues in opposing additional witnesses, giving Republicans sufficient votes to block the Democrats’ plea for more witnesses. While Huckabee said it would be great to see Joe Biden and his son, Hunter Biden, testify, he conceded that Democrats “are never going to allow that.” Because of that, Huckabee believes that Graham, chairman of the Senate Judiciary Committee, should open his own investigation:

“It’d be great to have Hunter and Joe Biden brought in to testify. The Democrats are never going to allow that. So what I think should happen, when this is all over, I hope Lindsey Graham will investigate how this started because he’s certainly capable as the chairman of the Judiciary Committee,” Huckabee told Marlow.

“Not to continue the impeachment. That needs to end,” he clarified. “But what should start up is a legitimate investigation into not only Hunter Biden, but the origin of the dossier. We should find out about this ‘whistleblower.’ Where did he get his information? Was he biased? Did he do this with some political intent? Was it because of his own personal feelings, or was it because he truly believed that there was something of national security at stake? And that should be a separate investigation not tied whatsoever to the impeachment sham.”

Asked what will happen once the trial wraps up, Huckabee said it depends on if the GOP will “show some spine and backbone and decide that they’ll open an investigation of their own.”

“Does that mean that we stop investigating, that everyone gets away with it aside from the president, to have had all this time wasted?” Marlow asked amid reports of the trial coming to an end. “Is that what it’s going to be?”

“It is, unless the Republicans show some spine and backbone and decide that they’ll open an investigation of their own,” Huckabee said, again calling on Graham to take action.

“Lindsey Graham has the power as the chairman of the Judiciary Committee to do it. The Republicans are in the majority. The Democrats did their own investigation in the House. It was a total disaster because they didn’t have anything … but this time, let the Democrats have their opportunity,” he continued, pointing out that Democrats could use the opportunity to call former National Security Adviser John Bolton as a witness.

“If they want to bring John Bolton in for this one, bring him in. Let’s hear from him. But he’s going to have to square what he may be saying in his book with what he said on television just after this phone call took place when he talked about the warm and cordial conversation the president had with the president of Ukraine,” he added.