The emergent Red Nation would occupy the majority of the central and southern United States and the Blue Nation would actually be three distinct regions: West Coast, Upper Midwest, and Northeast.
The Red Nation would, through its conservative legal, fiscal, and welfare policies drive liberals along with hordes of like-minded non-productive, social malcontents and misfits across the borders into the Blue Nation. The Blue Nation with its nonjudgemental, openhanded liberality would welcome one and all ultimately leading to a crisis arising from welfare bankruptcy and moral degeneration. Blue Nation would split into three smaller states; Blue West, Blue Central, and Blue East, with each striving to create its own version of liberal Utopia.
In the meantime, Red Nation would militarize and build effective frontier barriers to prevent the remigration of starving, diseased liberals, welfare layabouts, and illegals once Blue State economies collapsed. With its ready embrace of free markets and business friendly economic policies, Red Nation would attract the investment needed to create the new economic infrastructure needed to replace that lost through the partition of the nation.
A better solution would be to devolve the country and re-establish the states as sovereign. A return to the Articles of Confederation may be a solution. This is no more out of the ordinary than proposals for splitting the nation into two or more countries, and would be more peaceful.