- "Make no mistake, this is conduct that I think reaches the impeachment charge that is being contemplated by the House right now," Rep. Jackie Speier tells CNBC.
- Other congressional Democrats who have seen the complaint say the whistleblower complaint makes "credible" allegations.
- President Trump's request for Ukraine to look into Biden and his son was an abuse of power, says Michael Conway, former counsel to the United States House Judiciary Committee.
The whistleblower complaint that sounded the alarm on a phone call between U.S. President Donald Trump and Ukrainian President Volodymyr Zelensky makes strong case for impeachment, Rep. Jackie Speier told CNBC on Wednesday night.
On Tuesday, House Speaker Nancy Pelosi announced that the U.S. House of Representatives will begin an official impeachment inquiry into Trump over his efforts to push Ukraine to investigate a potential 2020 election rival, former Vice President Joe Biden.
"Make no mistake, this is conduct that I think reaches the impeachment charge that is being contemplated by the House right now," Speier, D-Calif. told "Street Signs" from Washington D.C. on Wednesday night.
When asked about the likelihood of Trump's impeachment, the congresswoman said: "I can assure you this complaint has shown all the signs of being a very compelling argument for impeachment."
"When the impeachment process started with Richard Nixon, there was very little support for it. But as more and more evidence was built up, it became more and more persuasive," the Democratic congresswoman said.
An impeachment process was started against Nixon because of the Watergate scandal, but he ultimately resigned from office before it came to a vote.
"We will allow the facts to take us where they will," Speier said, pointing out that the inquiry against Trump was still at an early stage.
The whistleblower's complaint, which was released to Congress on Wednesday, reportedly raised alarms about Trump's July 25 call with Zelensky. In a summary of the call released by the White House, Trump asked if Zelensky "can look into" Biden and his son, Hunter.
Democratic Rep. Adam Schiff, chairman of the House Intelligence committee, said the complaint's allegations were "very credible" and "deeply disturbing." Speier echoed Schiff's comments, saying the whistleblower "was comprehensive in his or her work ... and made a case for it being not only credible but urgent."
NBC News reported that the whistleblower complaint has been declassified and could be released as soon as Thursday.
The call was "alarming ... to most Americans that somehow the president would equate doing a favor ... for him with his re-election bid by asking the president of Ukraine to dig up dirt on his prospective opponent," Speier said.
"It is placing his interest before the American people, it is a breach of the public trust, it is a form of extortion, it's a shakedown, it has all the makings of a mob activity," she told CNBC.
Trump has maintained that the call was "perfect," and that there was no "quid pro quo." Justice Department officials have told NBC News that the call did not constitute a campaign violation and that what Trump asked for did not amount to a "thing of value."
Trump's behavior in the call was an abuse of power, said Michael Conway, former counsel to the United States House Judiciary Committee, when asked whether there was anything in the summary that would be an impeachable offense.
"The favor was to get dirt on his political opponent, that is such an abuse of power under our system," Conway said. "First of all, to involve a foreign government at all in our election process is improper, and to use the office of the presidency to do it."
The impeachment inquiry might not, however, lead to Trump actually being removed from office, Conway said. He doesn't think it's "likely at all," adding that an inquiry is just the first stage.
"(It) doesn't mean the House is ever going to vote to impeach," Conway said, adding that the Republican-controlled Senate is also "highly unlikely to convict" Trump leading to his removal from office.
Presidents Andrew Johnson and Bill Clinton are the only presidents to be impeached, while no president has ever been convicted and removed from office.
"The question is whether any Republicans will in any sense abandon President Trump," Conway said.
— CNBC's Jordan McDonald and Kevin Breuninger, as well as NBC News, contributed to this report.