We have not covered other issues, particularly the poor physical and mental shape of a majority of potential recruits. You would need six months at the equivalent of fat farms to have them lose weight and detoxify before you sent them to basic training. We had a draft up and running for over a year before Pearl Harbor but it wasn't until mid-1942 that American forces were available in the European theater. I doubt that China and Russia will wait for our prolonged training needs.
The draft is off the table for these and other reasons.
Red or blue state is irrelevant really. Go by county. There are areas in California, Maryland and Massachusetts every bit as conservative as anywhere. Likewise there are quite a few very liberal voting areas in Texas, Mississippi and Iowa. It all boils down largely to ethnicity and heritage.
Massive resistance would require almost immediate replacement of the banking, transportation, and other systems. The only way that could happen is organized resistance by a state or group of states and even then the dislocation would be horrific with most large employers being unable or unwilling to meet payroll, pay suppliers, etc.
And they could still raise troops from blue areas no matter how unpopular because if you hold political power from the barrel of a gun political unpopularity doesn't matter much. And they will blame us for the problem to increase the motivation of new recruits.
There is no example of "massive resistance" succeeding without a solid plurality of the country's elite pushing for it. As Machiavelli noted, the vast majority of people simply wish to be left alone and our own revolution would have gone nowhere without a substantial portion of the elites going along with it and having a ready political instrument in the form of the colonial governments and militias at hand. Show me where that is now and maybe I'll believe you.