From a New York Times story by Carl Hulse headlined “‘Three Johns’ Top the List of Potential Successors to Mitch McConnell”:

Senator Mitch McConnell’s second alarming medical episode before television cameras on Wednesday has renewed scrutiny on his health as well as speculation about possible replacements for the longtime leader should he be forced to step aside.

A change at the top would be significant for Senate Republicans, considering that Mr. McConnell has been their leader since 2007 and had been the No. 2 Republican for four years before taking the helm. This year, he became the longest-serving Senate leader in history, a milestone he had long sought.