WASHINGTON — The Supreme Court on Monday issued its first ruling in a case arising from the coronavirus pandemic, refusing to extend the deadline for absentee voting in Tuesday’s elections in Wisconsin by six days.

The vote was 5 to 4, with the court’s more conservative members in the majority. The split, with all of the justices appointed by Republicans endorsing the result sought by Republicans and all of the Democratic appointees in dissent, suggested that the court may struggle to maintain an image of nonpartisanship as it is called on to resolve what will almost certainly be a parade of election disputes this year.

The justices in the majority, in an unsigned opinion, said the wisdom of proceeding with an election in the midst of a health crisis was not before them.

“The court’s decision on the narrow question before the court should not be viewed as expressing an opinion on the broader question of whether to hold the election, or whether other reforms or modifications in election procedures in light of Covid-19 are appropriate,” the opinion said. “That point cannot be stressed enough.”