257 Democrats
178 Republicans
A 100 seat swing would look like this:
157 Democrats
278 Republicans
And Nancy Pelosi goes back to her closet office up in the attic of the Rayburn building.
Nice.
Today, we are -79 to the Dems (257-178=79).
A 100 seat swing would put us at +21 (-79 + 100 = +21)
Your math would actually be a 200 seat swing from current status...going from -79 to +121 = a 200 seat swing.