Gladys Sicknick, center, mother of Brian Sicknick, the Capitol Police officer who died from injuries sustained during the Jan. 6 mob attack on Congress, leaves a meeting with Republican Sen. Ron Johnson of Wisconsin after advocating for creation of an independent commission to investigate the assault, at the Capitol in Washington, Thursday, May 27, 2021. She is escorted by Harry Dunn, left, a U.S. Capitol Police officer who faced the rioters on Jan. 6.

WASHINGTON — Senate Republicans are poised to block the creation of a special commission to study the deadly Jan. 6 attack on the Capitol, dashing hopes for a bipartisan panel amid a GOP push to put the violent insurrection by Donald Trump's supporters behind them.

Broad Republican opposition was expected in what would be the first successful Senate filibuster of the Biden presidency, even as the family of a Capitol Police officer who died that day and other officers who battled rioters went office to office asking GOP senators to support the commission. The siege was the worst attack on the Capitol in 200 years and interrupted the certification of Democrat Joe Biden's win over Trump.

Though the bill passed the House earlier this month with the support of almost three dozen Republicans, GOP senators said they believe the commission would eventually be used against them politically. And former President Trump, who still has a firm hold on the party, has called it a “Democrat trap.”