The American Postal Workers Union is launching a national TV ad campaign promoting voting by mail. This comes as President Donald Trump has raised skepticism about mail-in ballots. He recently signed an executive order to put the Postal Service in the middle of election administration. The 30-second union ad features voters explaining why they vote by mail and will start airing in Ohio this week. The ad encourages voting by mail to be protected and expanded. Union President Jonathan Smith says postal workers should not be responsible for verifying voter eligibility, as would be required under Trump's order.

The U.S. Supreme Court is set to hear arguments over a Mississippi law that allows counting late-arriving mail ballots after Election Day. The high court on Monday will hear from Republicans and Libertarians who sued the state, arguing that federal Election Day statutes envision a single day for casting ballots, which would mean that grace periods for receiving mail ballots aren't allowed. The practice is a frequent target of President Donald Trump and allies who argue it delays vote tallies and leads to suspicions about the results, even though there is no evidence of fraud in late-arriving ballots. Grace periods for all mail ballots are allowed in 14 states, with an additional 15 granting extra time for military and overseas ballots to arrive.