On Dec. 6, Democratic Senator Raphael Warnock won a special runoff election in Georgia against Republican candidate Herschel Walker. Warnock’s victory gives Democrats a slim, but solid, majority of 51 to 49 in the Senate. The new majority allows Democrats to control everything from investigations and oversight to key legislation and committee placements.

On Dec. 9, Arizona Senator Kyrsten Sinema announced that she will register as a political Independent, but that is unlikely to impact the power balance in the next Senate. The Democratic majority already includes two Independents who caucus with them — Senators Bernie Sanders of Vermont and Angus King of Maine.

To unpack the many implications of the new Senate majority, we had Andy Wright, a member of Just Security’s Editorial Board and partner at the law firm K&L Gates in Washington, D.C. Andy is an expert on Congressional oversight and previously served in senior legal roles at the White House and on Congressional committees.