In the eight states along the Great Lakes (N.Y., Pennsylvania, Ohio, Indiana, Michigan, Illinois, Wisconsin, and Minnesota), Republicans gained four Senate seats, and 23 House seats.

But also, on the state-government level the GOP made important gains in 6 of those 8 states: In Michigan, Indiana, Ohio, Pennsylvania, Wisconsin, and Ohio, the GOP now controls both legislative chambers and the governorship — clutch for redistricting. In New York, Republicans won back the State Senate, limiting the Dems ability to control redistricting.