Story highlights Isakson is recovering from back surgery and is slowed by Parkinson's disease

Isakson's vote tied the tally at 50-50 and Pence the broke the tie

Washington (CNN) Sen. Johnny Isakson, who is recovering from back surgery, returned to the Capitol Thursday to cast a key vote to help advance a controversial measure related to Planned Parenthood funding.

The 72-year-old Georgia Republican, who also is slowed by Parkinson's disease, came off a Capitol elevator in a wheelchair with Vice President Mike Pence at his side around 11:30 a.m. ET and headed to the floor where the two cast votes on the measure. The vote had been held open for a full hour so Isakson, who had just landed at Reagan National Airport after a flight from Atlanta, could make it.

Isakson's vote tied the tally at 50-50 and Pence the broke the tie.

Their votes were needed because two Republicans -- Susan Collins of Maine and Lisa Murkowski, who are each supporters of Planned Parenthood -- voted against it. Republicans have a 52-48 majority and all Democrats voted no.

The measure in question would repeal an Obama administration rule that was designed to prevent states from blocking Title X funding from going to health care providers that perform abortions. Republicans are using a special legislative tool called the Congressional Review Act to repeal several Obama-era rules and regulations issued at the end of President Barack Obama's term.

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