Democrats called an "emergency" caucus meeting at the Capitol to discuss their options roughly 12 hours after new reports that the FBI is investigating extensive communications between the Trump campaign and Russian intelligence officers.
Senate Minority Leader Chuck Schumer called for Attorney General Jeff Sessions to recuse himself from the investigation into Russia's connections to the Trump campaign and other facets, including the phone calls that led to the resignation of former National Security Adviser Michael Flynn this week.
"We need to get all the facts, so in the days and weeks ahead, the Trump administration needs to answer some serious questions," the New York Democrat said Wednesday morning. "These questions must be asked by an independent and unbiased law enforcement authority."
As he headed to the meeting, Sen. Chris Murphy, a Connecticut Democrat, said anything less than a complete investigation would amount to a "coverup."
"We've got to look at what our options are to send a message that a cover-up is not OK," Murphy said. "By stopping a bipartisan, independent investigation from moving forward, we will continue to incentivize the separation of the intelligence forces from the executive. That's terrible for this country."
But Senate Republicans, including those who have been hawkish on Russia, held their ground against Democratic calls for deeper investigations.
"I think that first questions have to be answered and then to go from there," said Sen. John McCain, one of a handful of Republicans who has broken with his party in calling for a tough stand against Russia. "We need to find out a lot of basic information, because it is just the beginning of this, before we decide to move forward."
When asked if there should be an independent investigation of Flynn and the latest Russian revelations, Sen. Susan Collins, a Maine Republican who frequently breaks with her party, dismissed the idea.
"There is an independent investigation, it's being done by the Intelligence Committee," she said.
Members of the Senate Intelligence Committee who met yesterday to discuss Flynn's stunning resignation, said they were still plotting the timeline of their investigation but hoped to briefed soon by intelligence officials.
Sen. Joe Manchin, a West Virginia Democrat, said he was looking forward to reading the transcripts of Flynn's calls with the Russian ambassador to the US and having Flynn testify before the committee.
"Right now we're going for everything we can to make sure the committee's up and running and does it job," he said. "Once we get into it, all the different intelligence people will come in."
Sen. Marco Rubio, a Republican member of the intelligence panel, said he was confident in the investigation already underway.
"That's an ongoing situation and Flynn will be a part of it," said the Florida senator, who is scheduled to have dinner with Trump on Wednesday. "I'm confident in the process we put in place. It's bipartisan. There is strong support for it."
House Democrats are also pressing for an aggressive investigation, including asking for transcripts and calling for Flynn to testify.
However, House Speaker Paul Ryan and other top Republicans insist that any probe should be part of the existing House Intelligence Committee investigation.
Chairman Devin Nunes, of California, dismissed any move last night to create any outside panel, and all top GOP leaders continue to back him up and defer any questions on next steps to him.
California Rep. Adam Schiff, ranking member of that House committee, told reporters Wednesday he's meeting later with the chairman.