As he aims to build on Republican momentum in Wisconsin, Mitt Romney will be joined by a prominent local guest when he makes his first trip to the state as the presumptive GOP presidential nominee on Monday.
33 out of 100 seats are up for election. 51 are needed for a majority.
|Seats gained or lost||+2||-2|
* Includes two independent senators expected to caucus with the Democrats: Angus King (Maine) and Sen. Bernie Sanders (Vt.).
All 435 seats are up for election. 218 are needed for a majority.