Democrat Bill Foster was sworn into office today, his campaign announced. Foster defeated Republican Jim Oberweis on Saturday in the special election to fill former Speaker Dennis Hastert's Illinois seat. This leaves five vacant seats in the House after a total of 11 vacancies since the start of the 110th Congress.

Another vacancy will also likely close this week, as voters in Indiana's Indianapolis-based 7th District decide today between Democrat Andre Carson and Republican Jon Elrod. A poll conducted in mid-February showed Carson with a double-digit lead, though this race could be closer than that.

There are two competitive Republican primaries in open seats in Mississippi today, as we previewed in Politics Nation. Both the 1st and 3rd Districts are likely to remain in GOP hands, so the winner today will likely go on to win in November. The 1st District seat is currently vacant due to Roger Wicker's appointment to the Senate, but his seat won't be filled for the remainder of this Congress until the May 13 special election.