According to a recent post on , entitled ACA opponents are exploiting a drafting error in the Senate bill that eventually became the law.
The article states that "If the cases reach the high court, legal observers believe it is possible the conservative majority led by Chief Justice John Roberts would find the premium subsidies illegal, crippling the law's insurance expansion".
There is no hidden agenda here. The Republican hate the ACA. They believe it is a government overreach that is not in the best interest of the people or physicians. They will continue to attack the law at every opportunity.