Virginia and Maryland officials have much at stake in Thursday's expected Supreme Court ruling on President Obama's health care reforms after playing pivotal roles for their respective parties in the two-year public fight over the law.

Virginia Attorney General Ken Cuccinelli, a Republican, made Virginia the first state to file a legal challenge to the law in 2010. Maryland Gov. Martin O'Malley, a Democrat, remains one of its most vocal proponents.

The divergent approaches mean Thursday's decision will have vastly different impacts on the two states.

Maryland officials have stayed up to date with the Obama administration's timeline for implementing the law, which calls for states to set up health exchanges for uninsured residents to purchase coverage on an open market. Maryland already has its exchange in place, and lawmakers would have to decide quickly whether to keep it if the high court threw out Obama's law.

The law, if upheld, would allow about 350,000 uninsured Marylanders to find coverage.

"I have cautioned for some time that we should go slowly for just this moment," said Maryland House Minority Leader Anthony O'Donnell, R-Calvert/St. Mary's. "It could mean the wasting of millions that have been spent to implement a program that could come crashing apart."

Virginia Gov. Bob McDonnell, a harsh critic of the reforms, has balked at calls from Democratic and Republican lawmakers to create an exchange. The state estimates 520,000 Virginians would gain coverage under the law.

"The major players in the health care industry, insurance providers and hospitals, they all wanted us to be a little further along than we are now," said Virginia Del. Mark Sickles, D-Franconia. "Putting it off like we did has had fewer people understanding what [an exchange is] going to be."

If the law is upheld, Virginia, 48th in the country in Medicaid spending per capita, will have to accommodate more than 400,000 Medicaid recipients who will become eligible for benefits under the law. An audit released this week expressed doubt the state had the infrastructure to handle the surge.

Both states could find some additional money in their budgets if the law were struck down. Virginia would recoup $45 million to cover people already eligible for Medicaid benefits who have yet to apply. Officials expect those individuals would turn to the state for assistance if they were required to purchase insurance.

Maryland could recoup $16 million allocated for specialty care physicians.