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WASHINGTON - Senate Republicans are expected to use the filibuster Thursday to block a bill that would establish a bipartisan commission to investigate the Jan. 6 insurrection conducted by a pro-Trump mob at the Capitol.
The filibuster requires 60 senators to vote in favor of ending debates so bills can advance. The House already passed the bill with a share of Republican support, but the Senate’s 50-50 split makes that task more daunting.
And fewer than 10 GOP senators have signaled support for the measure.
RELATED: House passes bill to create investigative commission on Jan. 6 Capitol riot
A mob of Trump supporters stormed the Capitol on Jan. 6 while Congress held a joint session to count the electoral votes and certify Joe Biden’s election. Rioters engaged police in combat inside and outside of the building.
Four rioters died, including a woman police shot while she was among a crew trying to break into the House chamber. Capitol Police officer Brian Sicknick collapsed immediately after engaging with the rioters and died the next day.
His mother, Gladys Sicknick, pleaded with Congress to establish the commission.
RELATED: Family of fallen Capitol Police officer Brian Sicknick pushes for commission on US Capitol riot
"I suggest that all Congressmen and Senators who are against this bill visit my son’s grave in Arlington National Cemetery and, while there, think about what their hurtful decisions will do to those officers who will be there for them going forward," Sicknick said in a statement.
Democrats blamed Trump and his false claims that widespread election fraud cost him the election. Almost immediately, the issue became a loyalty test among Republicans, who have largely chosen the uneasy position of condemning the violence while supporting the former president.
Sen. Mitch McConnell, the chamber’s Republican leader, scolded Trump after acquitting him in his second impeachment trial — calling him responsible for provoking the mob.
Even so, the senior Senator from Kentucky has rejected the need for the commission because there are already investigations into the insurrection underway. McConnell claimed Democrats only want to litigate Trump into the future.
Pro-Trump rioters stormed the US Capitol as lawmakers were set to sign off on then-President-elect Joe Biden's electoral victory in what was supposed to be a routine process headed to Inauguration Day. (Photo by Tayfun Coskun/Anadolu Agency via Getty …
Should the bill fail in the Senate, it will likely reignite the debate on the fate of the filibuster. Critics have said it is a relic used to oppose civil rights measures long ago.
Supporters, like Sen. Joe Manchin, D-W.V., have said it encourages bipartisanship and debates. Manchin, a moderate Democrat, has positioned himself as the defender of the filibuster in a party that is increasingly ready to do away with it.
While he hasn’t signaled his position is changing, Manchin took issue with Republicans who would block the Jan. 6 commission bill.
"There is no excuse for any Republican to vote against this commission since Democrats have agreed to everything they asked for," Manchin said in a statement. "Mitch McConnell has made this his political position, thinking it will help his 2022 elections. They do not believe the truth will set you free, so they continue to live in fear."
This story was reported from Atlanta. The Associated Press contributed to this bill.