There is no endgame where Liberals win
One of three things will happen
1) People will finally wise the F*&@#&* up and vote them out
2) Conservatives will finally get fed up enough, CWII ensues and we wipe them from the face of the earth
3) The Latin Americans and/or Moslems reach the threshold in population where they will have the numbers to turn on and kill all the Liberals who once welcomed them with opened arms.
Unfortunately, #3 is the most likely scenario. Hopefully there will be some small pockets of Conservatives left to build on.