It will be thrown in chaos.
But there will still be many safe-R seats in Congress and state governments.
Not unlike the Democrats after the McGovern debacle. The Democrats racked up 242 seats in the House in 1972, and actually gained 2 seats in the Senate in 1972.
There were HUGE differences back then, however:
1. The seniority system was fully intact in Congress, with conservative Democrats from safe seats and voting records that frequently deviated from the national party line holding committee chairmanships.
2. The diminished partisan environment and the rise of ticket-splitting, which has been eroded since the 1990s.
3. The less "nationalized" nature of many races. Even Congressional races were often decided on purely local factors.