WASHINGTON -- The U.S. Senate is scheduled to vote Tuesday to kick off debate on legislation that would repeal Obamacare, but what's in store is still a mystery.

Majority Leader Mitch McConnell has yet to disclose whether he plans to immediately push a replacement for the 2010 health care law or simply a repeal-only plan, much like what the Senate voted on two years ago. Working with the slimmest of GOP majorities, it remains to be seen whether he has enough votes to advance either.

Both Georgia senators, Republicans David Perdue and Johnny Isakson, voted for a repeal-only effort in December 2015, when there was no political risk as it was headed for certain veto.

But with the GOP in control of the White House and both chambers of Congress for the first time in a decade, the pressure is suddenly immense. The health insurance of up to 1 million Georgians is at stake.

Read more: Senate to push for health care debate, but which plan?