The ACA will proceed, as it is mandatory spending. I understand that the shutdown only impacts discretionary spending. The Tea Party first demanded that the ACA be defunded, and as I understand then demanded that implementation be rolled back one year. Of course, if it were rolled back one year, the extremists would continue infinite exortion, and the ACA would never be implemented.
Let's hypothesize that the ACA is defunded or delayed.
What is then to prevent the Tea Party extremists to go on a power rampage with a series of short term CR's in which they systematically proceed to defund portions of other critical mandatory spending programs, including Medicare, Medicaid, and Social Security?