Roberts and Kennedy are there to provide a firewall for the moderate Republican insiders who want illegal immigration.
The GOP insiders are supported by the business interests who want cheap labor and dare I say it, also want Obamacare-Romneycare to bail them out of heathcare costs.
The Supremes may strike down a federal mandate, but allow states to mandate ala Romneycare which is what Willard mean when he speaks of “repealing” Obamacare.