Oregon's junior senator just did something that qualifies as remarkable in the current political climate: He read a letter by Coretta Scott King on the floor of the U.S. Senate.

Earlier tonight, U.S. Senate Majority Leader Mitch McConnell (R-Kentucky) squelched Sen. Elizabeth Warren (D-Massachusetts) in a floor debate tonight on the confirmation of President Donald Trump's Attorney General nominee, Sen. Jeff Sessions (R-Alabama).

Sen. Jeff Merkley (D-Oregon) rose to defend his colleague.

McConnell had cut Warren off from speaking, to her visible shock. The Republican leader charged that Warren had broken Senate rules on decorum by referencing a 1986 letter by the late Coretta Scott King regarding voter suppression efforts by Sessions.

Democrats reacted quickly and negatively to McConnell's attempted censorship, some noting that chamber rules against "impugning" other Senators did not apply to Presidential nominees. McConnell, for his part, explained that the decorum rule did not have an exception for factual information.

"Unbelievable," Merkley wrote on Twitter.

Before long, Merkley's own turn to speak came, and he did something other Democrats had not tried: He read portions of King's letter into the record from the Senate floor.

King, a leader of the black civil rights movement who was also the widow of  Martin Luther King, Jr., had written that Sessions had "reprehensible" effort at voter supression in Alabama. (A copy of the letter can be found here.)

"Mr. Sessions has used the awesome powers of his office," she wrote, "to intimidate and frighten elderly black voters."

The looming vote to confirm Sessions marks a test of Senate Democrats in terms of strategy, unity and resolve, even as public anger in non-Trump-voting states grows in response to his dubiously qualified cabinet appointments, judicially rebuked executive orders and belligerent promotion of "alternative facts."