Massachusetts Democrats will decide the latest head-to-head matchup between the party's moderate and progressive wings. This time, top progressives are backing the incumbent.

Oklahoma Republicans will return to the polls Tuesday to settle an expensive nomination fight for governor, while Democrats will pick a nominee for U.S. Senate.

South Carolina Republicans will return to the polls Tuesday for the fourth time since June to replace the late U.S. Sen. Lindsey Graham on the fall general election ballot.

Residents of Georgia's 13th Congressional District outside of Atlanta will get a new representative to Congress after a special election runoff Tuesday to replace the late Democratic Rep. David Scott, who died April 22.