Below is a graphic of the results of the 2014 Midterm Election in the House of Representatives. The GOP is on pace to gain at least 14 seats giving the Republicans the most seats in 80 years (1928).
The red areas are Congressional Districts won by Republicans; the blue are areas won by Democrats. The shaded districts are pickups and the lighter hues (pink / cyan) are races not yet called but where that party is leading.
Another way to look at it is with just two colors. Assuming the party's hold all the seats where they are leading the 2014 Election Map by Congressional District looks like this. WOW!