Merrick Garland, Biden's pick for attorney general, could face tricky political questions during his confirmation hearing before the Senate Judiciary Committee today. In the wake of the Jan. 6 attack on the Capitol, Garland and Democrats are expected to point to Garland's work prosecuting the Oklahoma City bombing as evidence of his ability to investigate and prosecute domestic terrorism.

"If confirmed, I will supervise the prosecution of white supremacists and others who stormed the Capitol on January 6 – a heinous attack that sought to disrupt a cornerstone of our democracy: the peaceful transfer of power to a newly elected government,” Garland will say.

Garland's opening statement also conveys a commitment to equity, saying that upholding the Civil Rights Act remains "urgent" for the Department of Justice. Garland has received ample bipartisan support, ahead of his confirmation hearings before Senate Judiciary Monday and Tuesday, 61 former federal judges and a bipartisan group of more than 150 former Justice Department officials have penned letters in support of Garland's confirmation.

-ABC News' Alexander Mallin and Benjamin Siegel

Rep. Trent Kelly, R-Miss., took to the House floor on Tuesday to speak in favor of his bill to name a Tupelo post office after U.S. Air Force Col. Carlyle “Smitty” Harris, a Vietnam prisoner of war who was held in the infamous "Hanoi Hilton."

The uncontroversial measure was slated to pass under the suspension of the House rules -- with debate expedited because it had the support of two-thirds of the chamber.

But in a surprise move, Rep. Sean Casten, D-Ill., blocked the measure, and instead forced the House to take a recorded vote on the bill Tuesday evening.

The reason? Kelly voted to overturn the election results on Jan. 6.

"As Representatives working every day on behalf of the American people, Rep. Casten believes that working with members regardless of political party is at the core of good public policy," Casten's chief of staff Cara Pavlock said in an email obtained by ABC News. "As a general matter, he does not suggest this action against members with whom we merely disagree, but that willingness to collaborate can only extend so far and to those that also hold the core value of upholding democracy."

"The vote to overturn the election results in the midst of a violent insurrection was a bridge too far," Pavlock wrote, adding that Casten also planned to vote against the post office renaming for that reason.

The bill did pass on a vote of 406-15.

The minor procedural dustup is one of many reminders of how Congress is still grappling with the aftermath of the Jan. 6 Capitol riot and that lawmakers are still coming to terms with how to approach colleagues who supported and amplified former President Donald Trump's efforts to undermine the results of the 2020 election.

-ABC News' Benjamin Siegel