The whistleblower's full complaint was made available to members of the House and Senate Intelligence Committees Wednesday evening before scheduled hearings Thursday with the Acting Director of National Intelligence Joseph Maguire.
"The complaint in my estimation was explosive. It was jaw-dropping," said Bay Area Congresswoman Jackie Speier, who was among those allowed to view the unredacted complaint.
Speier spoke with KTVU by phone, saying the documents suggest an abuse of power by President Trump who asked for the Ukraine President to help investigate a potential 2020 Democratic rival Joe Biden and Biden's son Hunter.
"To meet the standard of urgent, it has to show that it has ramifications for national security and there was no question that this was the case," said Speier.
One Republican, Senator Ben Sasse of Nebraska, said some of the contents were "troubling" but said Congress shouldn't rush to impeach.
House Minority Leader Kevin McCarthy introduced a resolution late Wednesday calling for disapproval of Speaker Pelosi's impeachment inquiry. The resolution was tabled.
On the campaign trail in San Francisco, Julian Castro, who said he was the first of the Democratic presidential candidates to call for impeachment, spoke at Manny's in the Mission District.
Castro also attended a Latin Heritage event at San Francisco City Hall and spoke out about the need for Congressional oversight.
"Whether you're liberal, or conservative or somewhere in between. You can see what's going on here. And it's completely inappropriate for a president to try and get a foreign leader to work with the U.S. government to do the dirty work, the political dirty work against a political opponent. I mean, who does that? Nobody should do that. It's completely outside the bounds of the way a President should act," said Castro.
The stakes are high. Fifteen Democrats in districts President Trump won in 2016 have come out in favor of an impeachment inquiry, but could face a fierce backlash if the impeachment inquiry backfires politically.
There are calls on both sides of the aisle not to rush the inquiry process.
"Allow the Intelligence Committee and other committees do their due diligence in bringing in persons of interest in to interview, to collect as much evidence as needed, and present it to the Judiciary Committee," said Speier.
If the Judiciary Committee recommends an impeachment vote, it would need 218 votes in order to pass and move to the next step, a Senate hearing.