Sen. John Thune John Randolph ThunePowell warns failure to reach COVID-19 deal could 'scar and damage' economy Senate Republicans signal openness to working with Biden Democrats scramble on COVID-19 relief amid division, Trump surprise MORE (R-S.D.) early Wednesday defended the decision to bar Sen. Elizabeth Warren Elizabeth WarrenNo new taxes for the ultra rich — fix bad tax policy instead Democrats back away from quick reversal of Trump tax cuts It's time for newspapers to stop endorsing presidential candidates MORE (D-Mass.) from speaking on the floor late Tuesday after she was accused of having impugned another senator.

"It was a clear violation of the rules ... rules say it, 'directly or indirectly impugning the character or conduct of another colleague,' and she clearly had done that. She crossed that line," Thune said on MSNBC's "Morning Joe."

"The whole message behind this was that the Senate's a place where collegiality is supposed to rule. There are rules. We're supposed to abide by those rules. If those rules are not adhered to, people need to be called out."

The Senate voted Tuesday to prevent Warren from speaking on the floor after Majority Leader Mitch McConnell Addison (Mitch) Mitchell McConnellSenate Republicans signal openness to working with Biden Hillicon Valley: DOJ indicts Chinese, Malaysian hackers accused of targeting over 100 organizations | GOP senators raise concerns over Oracle-TikTok deal | QAnon awareness jumps in new poll The Hill's Campaign Report: Biden asks if public can trust vaccine from Trump ahead of Election Day | Oklahoma health officials raised red flags before Trump rally MORE (R-Ky.) said her blistering comments about fellow Sen. Jeff Sessions Jefferson (Jeff) Beauregard SessionsTrump's policies on refugees are as simple as ABCs Ocasio-Cortez, Velázquez call for convention to decide Puerto Rico status White House officials voted by show of hands on 2018 family separations: report MORE (R-Ala.), President Trump's pick for attorney general, broke the chamber's rules.

ADVERTISEMENT

Senators rebuked Warren in a 49-43 party-line vote, rejecting Warren's push to overturn a ruling by Senate Republicans that she had violated the rule during a floor speech.

The move bars Warren from speaking on the floor until the Senate wraps up its debate on Sessions's nomination.

Under the Senate's Rule 19, senators are not allowed to "directly or indirectly, by any form of words impute to another Senator or to other Senators any conduct or motive unworthy or unbecoming a Senator."

On Tuesday night, Warren gave a speech against Sessions's nomination, arguing he wouldn't stand up to Trump's "campaign of bigotry." In her speech, she quoted a letter from the late Coretta Scott King, the civil rights activist and wife of Martin Luther King Jr.

Thune said Wednesday that Warren was "impugning the character of a colleague."

"In this case, Jeff Sessions, who most of who have served with him understand and know he's a man of absolute integrity," Thune said.

He added that the Massachusetts senator was in clear violation of the rules.

"The Senate is a collegial place, but most of us like to think of it as we're all part of a team," he said.

"And when one of your team members gets attacked, you typically defend them, and that's simply what happened last night."

He also called it "unfortunate" that more Democrats didn't step up and "acknowledge that that was crossing a line."