The Wall Street Journal explained the punt by the Supreme Court:

It
was a good day for Democrats and procrastinators yesterday as the
Supreme Court refused to hear Ohio’s appeal of its early voting law. But
while the Obama campaign got out the noisemakers, the decision tells us
less about the likely outcome in swing-state Ohio than it does about
Democrats’ strategy to intimidate the Justices on voting-law cases. Look
out, Chief Justice Roberts.

Passed by the Ohio legislature
in the spring, the Buckeye State’s law would have ended early voting in
the state three days before the November election day. The provision
was intended to give the state time to take account of the early votes
to prevent the possibility of early voters going to the ballot box for a
second time. To the chagrin of the Obama campaign, the law exempted
military and overseas voters who were allowed to continue their early
voting right up to Election Day.

Earlier this month, the
Sixth Circuit Court of Appeals said that the final three days of voting
could not be extended as a special exception for military voters.
Democrats spent most of Monday urging the court not to hear the appeal
of the case, calling the decision a test of the Justices’ politics and
the biggest deal since Bush v. Gore. Democracy Program Director Wendy
Weiser of the liberal Brennan Center for Justice told USA Today that
“There’s a risk to the court’s reputation in getting involved in these
cases.”