■ Senate Republicans were poised to block creating a commission to study the Jan. 6 Capitol riot.

WASHINGTON — Senate Republicans were poised Thursday to block the creation of a special commission to study the Jan. 6 attack on the Capitol.

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. A vote to cut off the filibuster was expected after midnight.

The bill passed the House earlier this month with the support of almost three dozen Republicans.

President Joe Biden, asked about the commission at a stop in Cleveland, said Thursday, “I can’t imagine anyone voting against” it.

Former President Donald Trump has called it a “Democrat trap.”

More than 400 people among the protesters have been arrested.

Senate Republican leader Mitch Mcconnell, who once said Trump was responsible for “provoking” the mob attack on the Capitol, said of Democrats: “They’d like to continue to litigate the former president, into the future.”

Texas Sen. John Cornyn, who once supported the idea of the commission, said he now believes Democrats are trying to use it as a political tool.

“I don’t think this is the only way to get to the bottom of what happened,” Cornyn said, noting that Senate committees are also looking at the siege.

Sen. Mike Rounds, D-S.D., said he believes there should be a commission, but he supports forming it after the Justice Department finishes its investigations and the 2022 election is over.