The northeast and west coast don't have enough in common to hold them together post-division. If there was a split, I think that it would be at least 6 areas, like this.
Alaska becomes its own thang.
California, Washington, Oregon, Hawaii, Nevada.
Everything north and east of Pennsylvania plus Maryland, Delaware, West Virginia, and DC.
Ohio, Indiana, Illinois, Wisconsin, Michigan, Minnesota. This would be the most politically divided area, but has enough in common to stay together.
North Dakota, South Dakota, Iowa, Nebraska, Kansas, Wyoming, Colorado, Utah, Idaho, Montana.
Texas, Louisiana, Oklahoma, Missouri, Arkansas, Mississippi, Tennessee, Kentucky, Alabama, Georgia, Carolinas, Virginia.
Unsure: Arizona, New Mexico, Florida. Florida actually could split itself up a few times, even.