The Senate will gain two new Democratic members on Wednesday, additions that will alter the balance of power in the chamber and could shake up the current committee structure.

Vice President Mike Pence is expected to be at the Capitol at noon for the swearing-in ceremony for Doug Jones of Alabama and former Minnesota Lt. Gov. Tina Smith.

Jones last month won the special election to fill Attorney General Jeff Sessions’ former Senate seat. Smith replaces Sen. Al Franken of Minnesota, who announced in December he would resign amidst mounting claims of sexual misconduct.

The addition of Jones will give Democrats an extra seat, reducing the Republican majority to 51-49. The slim margin could make it more difficult for the GOP to advance legislation on a party-line basis under the fast-track budget procedure known as reconciliation.

While they stayed united to pass a tax overhaul at the end of 2017 with no GOP defections, Senate Republicans failed to pass a repeal of the 2010 health care law after three GOP members joined with Democrats to doom the effort.

Senate Majority Leader Mitch McConnell has indicated he intends to pursue more bipartisan initiatives in 2018.

The additions could also put more pressure on President Donald Trump’s judicial nominees. Several individuals withdrew their nominations last year after facing criticism from some Senate Republicans. A simple majority is needed for confirmation.

Jones and Smith entering the Senate will force a reshuffling of the current committee structure, one that could reduce the two-member GOP majority on some panels — like the Senate Finance and Judiciary Committees — to one.

The chamber will need to pass a new organizing resolution to establish which committees the two new senators will serve on.

That measure, which is traditionally agreed to by unanimous consent, may need to include an adjustment to the number of Republican members allowed on some committees to reflect the tighter margins between the two parties.

A McConnell spokesman had no update on timing for when the resolution would reach the Senate floor.