Journalist Carl Bernstein has named 21 Republicans in the Senate he claimed had privately expressed "extreme contempt" for U.S. President Donald Trump and his "fitness" for the presidency.

Bernstein said the 21 Republican Party Senators who consider Trump worthless or deserving scorn, are: "Portman, Alexander, Sasse, Blunt, Collins, Murkowski, Cornyn, Thune, Romney, Braun, Young, Tim Scott, Rick Scott, Rubio, Grassley, Burr, Toomey, McSally, Moran, Roberts, Shelby."

The Watergate reporter said with few exceptions "their craven public silence has helped enable Trump's most grievous conduct - including undermining and discrediting the U.S. electoral system," The Independent quoted him as saying on Twitter.

The information, Bernstein said, came from "colleagues, staff members, lobbyists and White House aides," the report said. Some on Bernstein's list - Cornyn, Sasse, Collins and Murkowski - have denounced the president publicly.

However, other senators Bernstein named have publicly encouraged Trump to move on from the outcome - including Sen. Lisa Murkowski (Rep., Alaska) who said "it's time to start the full and formal transition process" for president-elect Joe Biden. As of Monday Trump still hadn't conceded defeat.

Bernstein said he wasn't violating any pledge of "journalistic confidentiality" in revealing the names.

Reporting for The Washington Post in 1974, Bernstein was at the forefront of revealing the Watergate scandal which led to former U.S. President Richard Nixon resigning. The 76-year old reporter recently said he was much more worried by Trump than he was by Nixon - because Trump is still refusing to accept defeat.

In an interview with CNN on Friday, Bernstein said that "many, if not most, of the individuals he named were happy to see Trump lose" as long as Republicans could dominate the Senate.