GOP sources are telling Roll Call that former Speaker Dennis Hastert (R-IL) will resign his seat in Congress effective later this year, triggering a special election to succeed him.

The exact date of Hastert's departure remains unknown, as a retirement announcement that he was expected to delivery today has been postponed.

Depending on Hastert's timeline, Illinois Governor Rod Blagojevich (D) could align the special election with the state's February 5th presidential primary. If that were the case, and if Barack Obama were still competitive in the presidential race by that date, some Democrats hope that having his presence on the ballot could boost the turnout of Democratic voters in the special election to replace Hastert.