The Senate Must Vote On President Obama's nomination for Supreme Court Justice before the end of his term.

Excerpt which best describes urgency:
How Scalia’s Death Will Affect Pending Cases Before the Supreme Court Massimo Calabresi @calabresim Feb. 13, 2016
The passing may have consequences for several important cases that are to be decided
When the Supreme Court justices split evenly on how to rule, the decision of the lower court stands. This can happen when a justice is recused from a case, or when there is a vacancy on the court. Scalia represented the fifth vote for conservatives on the court and in those cases that were expected to split 5-4 along ideological grounds, his death may affect the outcome.
In the event of a tie among the justices, the Supreme Court effectively upholds the lower court’s ruling and any opinions issued are considered non-binding.