WASHINGTON — Election officials are scrambling to prepare for a Supreme Court ruling this month that could upend laws in 14 states that allow late-arriving mail-in ballots to be counted.

The U.S. Supreme Court backed the Federal Communications Commission's system for levying fines, ruling on Thursday against wireless carriers AT&T (T.N), opens new tab ​and Verizon (VZ.N), opens new ta...

But the government also said companies did not have to pay the penalties right away, an apparent shift in practice expected to give the companies more flexibility.