WASHINGTON — A lawyer for Democrats on the House Intelligence Committee called President Donald Trump "a clear and present danger" as he summarized the party's case for impeaching him for having abused his power and obstructed a congressional investigation into his conduct in Urkaine.

The testimony from Daniel Goldman before the House Judiciary Committee came amid a crucial hearing at which lawyers for both Democrats and Republicans are making cases for and against impeachment. Earlier, Stephen Castor, a lawyer for Republicans called impeachment "baloney" and said Democrats had failed to make a compelling case.

At the heart of the Democrats' case is the allegation that Trump tried to leverage a White House meeting and military aid, sought by Ukraine to combat Russian military aggression, to pressure President Volodymyr Zelensky to launch an investigation of former vice president Joe Biden and his son Hunter Biden, as well as a probe of an unfounded theory that Kyiv conspired with Democrats to interfere in the 2016 presidential election.

Video: House Judiciary Committee Chairman Jerrold Nadler (D-N.Y.) delivered his opening statement during the panel's impeachment inquiry hearing into President Trump on Dec. 9. (The Washington Post)

Goldman, the top investigative counsel for the House Intelligence Committee, summarized the Democratic case for impeachment in his presentation.

"We are here today because Donald J. Trump, the 45th president of the United States, abused the power of his office, the American presidency, for his political and personal benefit," Goldman said. "As part of this scheme, President Trump applied increasing pressure on the president of Ukraine to publicly announce two investigations helpful to his personal reelection efforts."

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He later added: "When faced with the opening of an official impeachment inquiry into his conduct, President Trump launched an unprecedented campaign of obstruction of Congress - ordering executive branch agencies and government officials to defy subpoenas for documents and testimony."

Early on, Goldman pointed to Trump lawyer Rudy Giuliani's recent travels in Ukraine as evidence of the president's continued willingness to abuse his power.

Allegations pushed by Trump and Giuliani that Biden acted corruptly in his own actions toward Ukraine are "patently false," Goldman said.

"But that did not deter President Trump during his phone call with the Ukrainian president, and it does not appear to deter him today," he continued. "President Trump's persistent and continuing effort to coerce a foreign country to help him cheat to win an election is a clear and present danger to our free and fair elections and to our national security."

In his opening statement, Castor made the frequent Republican argument that Democrats have been seeking a reason to impeach Trump since January 2017 and have settled on Ukraine as their best option.

Video: House Republican counsel Stephen R. Castor gave his opening statement during the Judiciary Committee's impeachment inquiry hearing into President Trump on Dec. 9. (The Washington Post)

"To impeach a president who 63 million people voted for over eight lines in a call transcript is baloney," Castor said near the beginning of his remarks.

Calling impeachment an "obsession" for Democrats, Castor outlined the dozens of investigations into Trump, his business, his campaign and his administration undertaken by House committees since Democrats took the majority.

"This unfair process reflects the degree to which Democrats are obsessed with impeaching President Trump by any means necessary," Castor said. "The Democrats went searching for a set of facts on which to impeach the President - the emoluments clause, the president's business and financial records, the Mueller report and allegations of obstruction there - before settling on Ukraine."

Castor also chided Democrats for moving through the process too quickly and for not trying harder to get Trump administration witnesses to participate. The Trump administration has refused to cooperate with the inquiry, directing administration officials not to appear or provide documents.

Castor challenged the narrative laid out by the Democrats as making "a wonderful screenplay," but he claimed the facts were embellished to be "the most unflattering" for Trump.

Meanwhile Trump told reporters that he had "watched a little" of Monday's committee hearing.

"It's a disgrace, it's a hoax," he said at a White House event on school choice.

Castor also testified that Trump has cooperated with congressional oversight, when in fact the president has obstructed more than two dozen House investigations, including those looking at Trump's financial dealings and use of taxpayer dollars to boost the bottom line at Trump-branded hotels, according to an analysis by The Washington Post.

"The Trump administration has participated in oversight during the entire Congress until it got to this impeachment inquiry," Castor said.

It is unclear on what he based such a statement, when Trump has actually ignored every request for documents and testimony from Democrats. Trump bragged months ago, well before the Ukraine matter became public, that he instructed his administration officials to ignore "all the subpoenas" related to other investigations in the lower chamber.

He has continued to employ that strategy in the impeachment inquiry, directing his top officials involved in the Ukraine scheme not to testify to Congress about their own firsthand information.

Congressional experts have said that while oversight spats between the legislative and executive branches over witnesses and documents are usual, the sheer breadth of stonewalling from the Trump White House has been unprecedented.

Early in the GOP questioning time, Rep. Douglas Collins, R-Ga., drilled down on the House Intelligence Committee's decision to subpoena phone records from various figures in the impeachment inquiry.

Those records were partially disclosed in the Intelligence Committee's report, including calls involving Rep. Devin Nunes, R-Calif., and journalist John Solomon - prompting many Republicans to cry foul.

In response to questions from Collins, Goldman said that Democrats targeted records of "people who were involved in the investigation and who had already been subpoenaed by the committee for documents and testimony of their own."

"None of members of Congress, none of staff of Congress, none of journalists," he said. "We only did it to the subjects who were involved in the investigation, which is a very routine and standard investigative practice."

Republican members of the committee took issue with Nadler's decision to allow a Democratic Judiciary Committee lawyer to pose questions because the lawyer had presented an opening statement from the witness table earlier in the hearing.

In several tense exchanges with Nadler, GOP lawmakers argued that Barry Berke's dual role was inappropriate. Most of the interjections took place after Berke directed an aggressive line of questioning at Castor, counsel to Republicans, about Trump's motives in asking Zelensky to investigate the Bidens.

"I've been a judge, and I know you don't get to be a witness and a judge in the same case," said Rep. Louie Gohmert, R-Texas. Later, Gohmert asked, "How much money do you have to give to get to [do this]?"

Nadler said Gohmert should "not cast aspersions" on staff members and that he had not raised a proper point of order.

Republicans continued to disrupt the questioning, with Rep. Mike Johnson, R-La., claiming it was against the rules for Berke to ask Castor for his opinions. Rep. Andy Biggs, R-Ariz., repeated the objection to Berke's dual role.

"It is not a recognizable point of order," Nadler responded.

"I will point out that the gentleman has been designated by me to do this questioning," he said, citing a House resolution laying out rules for this phase of the impeachment inquiry. "It is in accordance with the rules of the House."

This article was written by Colby Itkowitz and John Wagner, reporters for The Washington Post.