Republican Senator John McCain is a critical vote in Congress's healthcare overhaul.
According to Reuters, he was described on Monday as upbeat and comfortable, but was still days away from traveling from Arizona to Washington after surgery to remove a blood clot from his head.
McCain's unexpected surgery forced Senate Majority Leader Mitch McConnell to postpone a healthcare vote, which threw the timing of the debate into uncertainty.
McCain's support is vital for the bill, which needs the backing of at least 50 of the 52 Republicans in the 100-member Senate.
Since changes in cabin pressure are dangerous following such operations, McCain will not be able to fly back to Washington D.C.
Instead, he will need to make a cross-country road trip, which will take several days.
Additionally, medical experts say his at-home recovery is likely to take a week or so..