Like Democrats who spoke before him, Rep. Dan Goldman, D-N.Y., reiterated that the hearing has no witnesses testifying with "direct knowledge of the evidence to determine that there is a basis for this impeachment inquiry."

"And this is an impeachment inquiry," he continued.

There has been no new evidence or knowledge so far in this hearing, he said.

"So why don't we have some of the fact witnesses here?" Goldman said. "The reason is, you bring in the fact witnesses and your case goes down the drain."

Rep. Katie Porter, D-Calif., made a point to highlight House Speaker Kevin McCarthy's past remarks regarding an impeachment inquiry.

"A veteran of several impeachments said an impeachment without a floor vote by the Congress would create a process completely devoid of any merit or legitimacy," Porter said.

She held up a poster featuring a photo of McCarthy and his quote, made over former President Donald Trump's 2019 impeachment inquiry.

"This House vote didn't happen," Porter continued. "We have not followed what the speaker himself, Mr. McCarthy, has said is the process that we should be following so that an impeachment inquiry would have merit or legitimacy. Which is something that I think all Americans on both sides of the aisle should expect investigations or inquiries like this to have."

After a brief recess, a Republican on the House Oversight Committee pushed back against Democrats' criticism that the hearing was unnecessary and improper.

Rep. William Timmons R-S.C. contended that there was enough evidence against Hunter Biden to start the inquiry. Timmons acknowledged that the evidence was "circumstantial" but stressed that lawmakers needed to do due diligence.

"The Congress has a duty to determine whether Joe Biden was a loving father taken advantage of by a delinquent son or a knowingly participant complicit in the scheme and financially compensated for his role. That's why we are here today, to answer that simple question," he said.

Timmons added that the panel will subpoena Hunter Biden's "personal bank records, various business records, invoices and contracts."

"We are doing this because the Department of Justice, FBI and the IRS refuse to do that their job," he claimed, without evidence.

Rep. Melanie Stansbury, D-N.M., was the latest Democrat to display Trump's social media posts behind her as she accused Republicans of doing his bidding.

"It's a campaign strategy ... we see the long arms -- but tiny hands -- of Donald Trump, and his fingerprints all over this impeachment," she said.

Republicans have largely ignored Democrats' jabs against Trump and his indictments, though one GOP lawmaker taunted Democrats.

"I love the fact that Trump lives rent-free in the Democrats' heads every day, that is a beautiful thing, even though we are here talking about the impeachment inquiry of Joe Biden," Rep. Lisa McClain, R-Mich., said.

1:57

Democrats tear into GOP over ‘sham’ impeachment inquiry

In closing remarks, House Oversight Committee Chairman James Comer, R-Ky., said he will subpoena bank records "today" while arguing that further investigation is needed into President Joe Biden's role in his family's business dealings.

"One of those steps is gaining insight into where the Biden's foreign money ended up, for what purposes," Comer said. "Today, I will subpoena the bank records of Hunter Biden, James Biden and their affiliated companies."