Hunter Biden

Rudy Giuliani, President Trump's personal attorney, says the president should not back away from investigating Joe Biden even after Trump's expected acquittal Wednesday by the U.S. Senate.

"Absolutely, 100%," Giuliani told NPR's Steve Inskeep in an interview Tuesday. "I would have no problem with him doing it. In fact, I'd have a problem with him not doing it. I think he would be saying that Joe Biden can get away with selling out the United States, making us a fool in the Ukraine."

Updated at 10:56 p.m. ET

Senators weighing impeachment charges against President Trump spent Thursday firing questions at lawyers as they did the day before, just as the prospect of former national security adviser John Bolton's appearance as a witness continues to stoke speculation. The Senate will enter its next phase Friday — considering whether to allow witnesses and evidence.

Republican lawmakers are asking that the impeachment inquiry into President Trump hear publicly from Hunter Biden and the anonymous whistleblower whose allegations prompted the probe.

In a letter to Democratic Rep. Adam Schiff, who is leading the inquiry, Republican Rep. Devin Nunes said that calling these witnesses would help ensure the investigation "treats the President with fairness."

The fourth Democratic debate was a long one, about three hours, and ended after 11 p.m. ET.

You might not have made it through the whole thing, but there were some potentially consequential moments.

Here are six takeaways:

1. The scrutiny came for Warren, and her vulnerabilities were exposed some

Sen. Elizabeth Warren of Massachusetts was under fire Tuesday night from several opponents, and when that happens to a candidate, you know they're a front-runner.

Ukraine was bound to come up during Tuesday's Democratic presidential debate at some point, but when it did, it quickly became clear that neither former Vice President Joe Biden nor his primary opponents wanted to focus on it.

With the debate's second question, Biden was given a chance to address the unfounded allegations lobbed by President Trump: that Biden used his federal power to corruptly favor a Ukrainian gas company that was paying his son, Hunter.

In an interview with ABC News that aired Tuesday morning, Hunter Biden said his involvement in the board of Ukrainian gas company Burisma was, in retrospect, "poor judgment on my part," although he said he did "nothing wrong at all." Biden asked, "was it poor judgment to be in the middle of something that is ... a swamp in many ways? Yeah."

Biden also reiterated that he will not work for any foreign companies should his father become president.