In December of that year, Senator Tim Johnson, Democrat of South Dakota, had a cerebral hemorrhage, putting the slim, newly won Democratic majority in jeopardy. Though he was gone for months, Mr. Johnson ultimately returned the next fall and won re-election in 2008 despite continuing health struggles.
In another recent case, Senator Mark Kirk, Republican of Illinois, had a stroke in January 2012 and was gone almost an entire year. No requirement exists for senators to step aside for health reasons if they choose not to, and there are many earlier instances of ill senators being away from Washington for lengthy periods, forcing their colleagues to adjust accordingly.
With Democrats able to approve a nominee themselves with their 50-vote majority, Republicans have so far signaled that they do not intend to dig in too hard against the pick, allowing them to show that Supreme Court confirmations can be conducted without becoming hyperpartisan spectacles. But any uncertainty about the Democratic ability to produce a sure 50 votes could quickly change that calculation and give Republicans more leverage over the nominee and the proceedings themselves.
Based on what has happened in the past, Republicans will tread carefully, not wanting to be seen as trying to gain advantage from the illness of a colleague and recognizing that like many things in the Senate, the tables can quickly turn.
On Wednesday, Senator Mitch McConnell, Republican of Kentucky and the minority leader, said that the entire Senate was “praying and pulling” for Mr. Luján and that it “was encouraging to read that our friend and colleague is expected to make a full recovery.”
Though Mr. Luján’s medical issue was more serious, the Senate has already contended with frequent absences this year as members dealt with positive coronavirus tests and family issues, forcing leaders of both parties to keep close track of attendance to guide their scheduling. Mr. Luján’s condition and the approach of a Supreme Court debate have now put such issues in the spotlight.
“That’s just what we live with every day in a 50-50 Senate,” said Senator Debbie Stabenow, Democrat of Michigan. “We are all human beings, and something can happen to someone at any time.”
Emily Cochrane and Annie Karni contributed reporting.