The Constitution also says an appointment is only made on the advice and consent of the Senate. No Senate consent, no appointment. The Senate made it pretty clear that they weren't going to consent to the appointment of Garland.
Now, if Obama had been in his first term, the Senate would understand that it could not thwart justice by understaffing the court indefinitely, and since all of the potential appointees would then be coming from Obama, so they would have to accept at least one of his proposed candidates within a reasonable period of time (that time might still have been beyond the 2016 election).
True, but they are sure when they are frail and ill. It's an uncommon kind of arrogance that persuades a judge to continue to sit to make extraordinarily important decisions affecting her fellow citizens when she knows she is going be dimished and distracted by her health challenges. It's an uncommon degree of detachment from humanity that persuades a judge to continue on with her work instead of focussing on her family and relationships when she knows her time is drawing to a close. Moral of the story? Old, frail judges can often exercise poor judgement - in their decisions, and in their lives.
